Answer:
10.
Step-by-step explanation:
x^2 + 5x = 150
x^2 + 5x - 150 = 0
This equation will factor:
(x - 10)(x + 15) = 0
x - 10 = 0 or x + 15 = 0, so:
x = 10 or -15.
Erm
x+y=6
xy=12
x+y=6
y=6-x
sub back
xy=12
x(6-x)=12
6x-x^2=12
x^2-6x=-12
x^2-6x+12=0
quadratic formula
for
ax²+bx+c=0

for
x²-6x+12=0
a=1
b=-6
c=12
and remember that √-1=i






x=3+/-i√3
the numbers are 3+i√3 and 3-i√3
no real numbers tho
7.4 is your final answer, hope that help, one decimal place is the first number after the decimal.
2x - 6y = 12
so we pick any number for x and then solve for y
lets say x = 0
2(0) - 6y = 12
-6y = 12
y = -12/6
y = -2....so when x = 0, y = -2....(0,-2) <== one point
lets say x = 1
2(1) - 6x = 12
2 - 6x = 12
-6x = 12 - 2
-6x = 10
x = -10/6
x = - 5/3...so when x = 1, y = -5/3....(1,-5/3) <== another point
Lets say x = 2
2(2) - 6y = 12
4 - 6y = 12
-6y = 12 - 4
-6y = 8
y = -8/6
y = - 4/3....so when x = 2, y = -4/3.....(2,-4/3) <== another point
lets say x = 3
2(3) - 6y = 12
6 - 6y = 12
-6y = 12 - 6
-6y = 6
y = -6/6
y = -1....so when x = 3, y = -1.....(3,-1) <== another point
now there is 4 points.