You can use it to find the area of something
y = x^2 + 2x...eqn 1
y = 3x + 20...eqn 2
subst for y in eqn 1...
=> x^2 +2x = 3x +20
=> x^2 - x - 20 =0
=> (x-5) (x+4) =0
=> x = 5 or -4
for x =5, y = 35 (sub for x in eqn 1 or 2)
for x = -4, y = 8 (sub for x in eqn 1 or 2)
<span>That depends on what you mean by "pound" and "ounce."
There are 16 English ounces in an English pound. There are 12 troy ounces in a troy pound.</span>
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We can separate the shape into a rectangle and a square
the area of the rectangle :

the area of the square:

the area of the whole shape:

hope this helps
Sure, that's easy! Here's one
5x + 7 = 162
If I wanted to solve this equation, I would break it down. I'd subtract the result (162) by 7
162 - 7 = 155.
From there I just divide that by 5!
155 / 5 = 31
There it is! Ultimate proof that x is in fact 31!