Factor:
<span>30n - 40 = 10(3n - 4)
hope it helps</span>
Answer:

Step-by-step explanation:
The given expression is
.
The technique that can be used to factor this polynomial is the difference of two squares.
We rewrite the two expressions as;

Recall that;



Answer:
x=10, y = -20
Step-by-step explanation:
y = –5x + 30
x = 10
Substitute the second equation into the first
y = –5*10 + 30
y = -50 +30
y = -20
x=10, y = -20
To solve for this, set up a proportion.
21/40 = x/100.
Cross multiply the fraction's numerators with the denominators;
21 x 100, 40 and x.
2100/40x.
Divide both numbers by 40 to get x.
2100/40 = 52.5
21 is 52.5% of 40.
I hope this helps!