What is 42= -7 × (z - 3)?

z=3

Step-by-step explanation:

42=−7(z−3)

Simplify both sides of the equation.

42=−7(z−3)

42=(−7)(z)+(−7)(−3)(Distribute)

42=−7z+21

Flip the equation.

−7z+21=42

Subtract 21 from both sides.

−7z+21−21=42−21

−7z=21

Divide both sides by -7.

-7z/-7=21/7

z=3

b

step-by-step explanation:

calculate the scale factor as the ratio of corresponding sides, image to original, that is

scale factor = = = = 1

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