What is
3x-y=9
2x-y=7

x=2 and y= -3

Step-by-step explanation:

This is a simultaneous equation. To solve this type of equation, there are three methods; substitution, Elimination and Graphical.

But here, we would be using the substitution method.

3x-y=9 Equation 1

2x-y=7. Equation 2

Getting y from equation 2, we have

-y= 7-2x

Multiply both sides by -

y= 2x-7 Equation 3

Substituting y for 2x-7 in equation 1, we have

3x- (2x-7)=9

3x-2x+7=9

x+7=9

x=9-7

x=2

Substituting x as 2 in equation 3

y=2x-7

y= 2(2)-7

y= 4-7

y= -3

for this pair of functions g(x)=x-2 and f(x)=|x| is (g o f)(a)= |a| -2

step-by-step explanation:

g(x)=x-2

f(x)=|x|

(g o f)(a)=?

(g o f)(x)=g(f(x))

(g o f)(x)=g(|x|)

(g o f)(x)=|x|-2

(g o f)(a)=|a|-2