Answer:
second equation :
( 20x² — 2xy — 42y² )
Step-by-step explanation:
expand the two brackets.
Answer:
60
Step-by-step explanation:
400-160=240
240/4=60
9We have such eqation
Q

/*9 (multiply both sides by 9)
9Q+5=

/-5 both sides
9Q=

9Q=

9Q=

9Q=-

/:9 divide both sides by 9
Q=-

Q
![\frac{21}{6*9} =- \frac{21}{54}=[tex] \frac{7}{18}](https://tex.z-dn.net/?f=%20%5Cfrac%7B21%7D%7B6%2A9%7D%20%3D-%20%5Cfrac%7B21%7D%7B54%7D%3D%5Btex%5D%20%5Cfrac%7B7%7D%7B18%7D%20)
- its the answer
So to find the answer you want to isolate the y. So the first thing you want to do is to move everything to the opposite side of the = sign. You start by adding 10 to both sides.
10+ 5y -10 = -25 +10
5y = -15.
the tens cancel out on the left side and on the right you get left with -15/
Since y is being multiplied by 5 you always want to do the opposite so you divide by 5.
5y/5 = -15/5
y = -3
It's hard to explain but you just have to remember that what you do to one side you must do to the other to keep the equation balanced.