3x - 5y = 18 over
-10x + 5y = 10
Add them because the 5y's have the right symbols for us to add
-7x = 28
Divide
x = -4
Now you can plug in -4 for x in one equation, I would use the first equation!
3(-4) - 5y = 18
-12 - 5y = 18
Add 12
-5y = 30
Divide
y = -6
Your solutions are going to be:
x = -4
y = -6
To check your work plug x and y into one equation:
3(-4) - 5(-6) = 18
-12 + 30 = 18
18 = 18
Since 18 does equal 18 you know that your solution's work!
We have that
2x²=450 ----------> x²=450/2----------> x=√225
x1=+15
x2=-15
<span>a reasonable length measurement should be positive
</span>therefore
the answer is
<span>The solutions are -15 and 15, but only 15 is a reasonable side length.</span>
To find the surface area of a prism (or any other geometric solid) we open the solid like a carton box and flatten it out to find all included geometric forms. To find the volume of a prism (it doesn't matter if it is rectangular or triangular) we multiply the area of the base, called the base area B, by the height h.
This info should help you.
