Algebra 1a

Question

What is the solution of the system? 

y=10x-2

y=-7x+3 

 

A. (5/17,16/17)

B. (4/15,16/19)

C.(-5/17,16/19)

D.(3/17,5/17)

Answer 1

Since both equations give expressions for y in terms of x, you can just set the two expressions equal to each other:

 

10x - 2 = -7x + 3

 

That gives you an equation that you can solve for x

 

Add 2 to both sidesL

10x = 7x + 5

 

Add 7x to both sides:

17x = 5

 

Divide both sides by 17

 

x = 5/17

 

Only one of the choices shows an x value of 5/17, so that must be it.

 

Answer 2

Since  y = 10x - 2 and y = -7x + 3, 

 

10x - 2 = -7x + 3

        17x = 5

            x = 5/17 and y = 10(5/17) - 2 = 50/17 - 34/ 17 = 16/17

 

ANSWER:  A