Question

Plzzz help me ??????

Answer 1

2 hours

First find the equation for car 2.

Difference in y/ difference in X = gradient.

20/1 = 20

Find the y intercept where x = 0.

y intercept = 40

Equation: y = 20x + 40

Use simultaneous equations to find the point at which they're the same distance.

Equate the equations.

30x + 20 = 20x + 40

Out it into the formula Ax = b so you have all the X's on one side and all the integers on the other.

30x + 20 - 20x = 20x + 40 - 20x

10x +20 = 40

10x + 20 - 20 = 40 - 20

10x = 20

10x / 10 = 20 / 10

x = 2

2 hours will pass.

Substitute X for 2 to check it's correct.

30x + 20 = 30 * 2 + 20 = 60 + 20 = 80

20x + 40 = 20 * 2 + 40 = 40 + 40 = 80