Answer:
I think that the rectangles,L's and I'm not sure about the other ones
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:
no. see below
Step-by-step explanation:
This much of Josh's working is correct:
x^2-6x=7
x^2-6x+9=7+9
(x-3)^2=16
At this point Josh apparently overlooked the fact that he needed to take the square root of both sides of the equation. Had he done that, he would have ...
x -3 = ±4
x = 3+4 . . . or . . . 3 -4
x = 7 or -1
_____
Josh reported values of x that would match ...
x -3 = ±16
He <em>violated the equal sign</em> by taking the square root on the left, and multiplying by ±1 on the right. Doing different operations on the two sides of the equation will mean the value of x is changed to something other than what you're looking for.