Answer:
-3(-3x + 4) = 9x - 12
Step-by-step explanation:
-3( Ax + 4) = 9x - 12
-3Ax -12 = 9x - 12
Equating coefficients of x terms on both sides :
-3A = 9
A = -3
Therefore, -3(-3x + 4) = 9x - 12
Answer:
88.90 cm
Step-by-step explanation:
A)
The question tells us that
y + z = 180
And
y=3x+20
z=x
So we put them in the first formula:
y + z = 180
(3x + 20) + x = 180
Add and get x to one side:
4x + 20 = 180
4x + 20 - 20 = 180-20
4x = 160
Divide both sides by 4
x = 40
B)
Put x back in to equation to get size of each angle:
Y =3x +20
Y=3(40)+20
Y=120+20
Y=140
Z=x
Z=40
Verify: y+z=180
140+40=180
180=180
Answer: The last line is a mistake
Step-by-step explanation: because you are not supposed to combine something that has a term and something that doesn't. So it should just stay has 40g+24