3x=4y
x+y=21
x = 21-y
3(21-y)=4y
63-3y=4y
63=7y
y=9
x+y=21
x+9=21
x=12
answer is (12, 9)
V = PI x r^2 x H
3.14 x 9^2 x 22 = 5595.48 = 5595 cm^3
<span> 7,200,000 written in scientific notation
=7.2 x 10^6
answer is </span><span>D. 7.2 x 10^6</span>
Answer:
x=-4 and y=10
Step-by-step explanation:
Use the second equation to make y=x+6
sub y=x+6 into the first equation
-x-2*(x+6)=0
-x-2x-12=0
-3x-12=0
3x=-12
x=-4
Now sub x=-4 into the second equation
-(-4)+y=6
y=6+4
y=10
Step-by-step explanation:
s = 2/3
because A = SxS = 2/3 x 2/3 = 4/9