Answer:

Step-by-step explanation:
Do FOIL, first outside inside last
3x × 3x = 9x^2
3x × -7 = -21x
7 × 3x = 21x
7 × -7 = -49

So it would just be 9x^2 - 49
Answer:
The proposed equation is solved as follows:
2X + 7 = 21
2X = 21 - 7
2X = 14
X = 14 / 2
X = 7
The value of X is 7.
A first degree equation is an algebraic equation in which each term is either a constant or a product of a fixed term on a single variable. Therefore, this equation is a first degree one, since it only has a single variable, which is X.
Let the two integers be x and x+1
(x+1)^2-x^2=21
x^2+2x+1-x^2=21
2x+1=21
2x=20
x=10
then x=10, x+1
10+1=11
the two integers are 10, 11
3/4 of a bushel is 75%, 2/3 of a bushel is 66.67% about. Being that both cost $9 the first store who is selling 3/4 of a bushel is a better deal because you get more for what you pay for.