Linear · Apply · 5.3

Apply mastery.

Mixed practice: translate the situation into two equations, choose a method, solve, and check both answers make sense in context.

01 / THE IDEA

See it work.

Watch the method

Apply mastery

Translate, solve, and interpret both answers.

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{y=x+2y=3x2\begin{cases} y = x + 2 \\ y = 3x - 2 \end{cases}
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1

The system

Two lines — the solution is the point on both.

y=x+2;  y=3x2y = x + 2;\; y = 3x - 2
2

Substitute one equation into the other

Solve for x, then back-substitute for y.

x=2x = 2
3

The solution

Write the intersection point.

(2,4)(2, 4)
02 / YOUR TURN

Practice until it feels automatic.

Your turn

Work it out.

Type (x, y).

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best 0
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Answer:
— / WHY IT WORKS

The idea underneath.

The full routine

Define variables, write two equations, solve, and interpret the solution.

Why it works

Story → two equations → point.

03 / WORKED EXAMPLES

From easy to tricky.

EX 1easy

Solve the system: y=-x-4 and y=-2x-5. Give the point (x, y).

1

The system

Two lines — the solution is the point on both. y = -x - 4;\; y = -2x - 5

2

Substitute one equation into the other

Solve for x, then back-substitute for y. x = -1

3

The solution

Write the intersection point. (-1, -3)

EX 2medium

Solve the system: y=-2x+11 and y=-x+7. Give the point (x, y).

1

The system

Two lines — the solution is the point on both. y = -2x + 11;\; y = -x + 7

2

Substitute one equation into the other

Solve for x, then back-substitute for y. x = 4

3

The solution

Write the intersection point. (4, 3)

EX 3hard

Solve the system: y=2x-5 and y=3x-9. Give the point (x, y).

1

The system

Two lines — the solution is the point on both. y = 2x - 5;\; y = 3x - 9

2

Substitute one equation into the other

Solve for x, then back-substitute for y. x = 4

3

The solution

Write the intersection point. (4, 3)

04 / COMMON TRAPS

Where students slip.

Trap

Rushing the setup.

Fix

A careful pair of equations makes solving easy.

Trap

Not checking the answer.

Fix

Substitute back into both.

05 / QUIZ

Test yourself.

The Test

12 problems across three tiers. Auto-graded on submit. Hints and a full walkthrough on every question. Your work is saved on this device — sign in to keep it across devices.

0/12Answered
How to answerType just the value. Formatting won't trip you up — we ignore spaces, capital letters, commas, and subscript style, so t₁ = 5, d = 3 and t1=5,d=3 both count. For a list of numbers, separate them with commas (e.g. 3, 10, 17).
Core

Core (4)

C1

Solve the system: y=-x-4 and y=-2x-5. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.
C2

Solve the system: y=x-4 and y=-2x-1. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.
C3

Solve the system: y=-x+5 and y=-2x+6. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.
C4

Solve the system: y=-x+2 and y=3x-10. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.
Apply

Apply (4)

A1

Solve the system: y=2x-3 and y=-2x+1. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.
A2

Solve the system: y=-2x-7 and y=-3x-10. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.
A3

Solve the system: y=x-3 and y=-x+5. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.
A4

Solve the system: y=x+2 and y=-x-4. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.
Extension

Extension (4)

E1

Solve the system: y=2x-5 and y=-2x-1. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.
E2

Solve the system: y=-x+6 and y=x-2. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.
E3

Solve the system: y=-x+4 and y=2x+7. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.
E4

Solve the system: y=2x+4 and y=3x+7. Give the point (x, y).

Need a hint?
  • Set up two equations.
  • Solve and check both.