Y=mx+b
m=slope
b=yint
find slope
slope between (x1,y1) and (x2,y2) is (y1-y2)/(x1-x2)
given
(-3,5) and (1,1)
slope=(5-1)/(-3-1)=4/-4=-1
y=-1x+b
find b
when x=1, then y=1
1=-1(1)+b
1=-1+b
add 1
2=b
y=-x+2
(a) 95 = (x+7)*(x-7)
(b) 95 = (x+7)*(x-7)
Expand the brackets:
95 = x² -7x + 7x -49 = x² - 49
Subtract x² from both sides:
95-x² = -49
Subtract 95 from both sides:
-x²=-49-95
-x²= -144
Divide both sides by -1 to get rid of the negative numbers:
-x²/-1=-144/-1
x²=144
Take the square root of 144:
x = ± squareroot of 144
x = 12 or -12
x = 12 because you cannot have a negative age so Trina is 12 years old.
The shirts were sold at $15 each.
<span>I believe its 4.5
I could be wrong though</span>
The answer is (15,0) because the format is (x,y) so (15,0) means that it is on the x axis only !
