Answer:
3n
Step-by-step explanation:
We can see that the 3 gets distributed into the parentheses since there is a +21 on the right (3×7=21) so we also have to distribute the 3 to the n
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.
To answer this (specifically the first one) you have to count how many spaces each point moves. (How many spaces up/down does it go? Left/right?) then you put rise (up/down) over run (left/right) and you should get the slope!
When you have something like this, all you need to do is substitute the values, the last is for what value of x
For the first one;
((x^2+1)+(x-2))(2)
(x^2+x-1)(2)
(2)^2+(2)-1
4+2-1
5
For the second one;
((x^2+1)-(x-2))(3)
(x^2-x+3)(3)
(3)^2-(3)+3
9-3+3
9
For the last one;
3(x^2+1)(7)+2(x-2)(3)
3((7)^2+7)+2((3)-2)
3(49+7)+2(3-2)
3(56)+2(1)
168+2
170
