Simplify this expression 7p+6q-2p+q

a) 8x+6a

b)5q+7q

Step-by-step explanation:

a) we need to combine the like(same) terms(with same variable) together

same terms: 3x and 5x

                      2a and 4a

so

3x+5x=8x

2a+4a=6a

8x+6a

b)a) we need to combine the like(same) terms together

same terms: 7p-2p=5q

                     6q+q=7q

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.