Answer:
D
Step-by-step explanation:
2y=10x
Divide both sides by 2.
y=5x
Now substitute this into the second equation.
Answer:
The product is the difference of squares is 
Step-by-step explanation:
Explanation
- The given expression is (x y-9)(x y+9).
- We have to multiply the given expression.
- Square the first term xy. Square the last term 9 .

Answer:
the answer is -8 or 7
Step-by-step explanation:
Sorry im not good w negatives...
Answer:
$10
Step-by-step explanation:
Let a = the amount Angela has saved.
Let e = the amount Eli has saved.
"Eli has saved $8 more than 1/3 of Angela's savings."
e = a/3 + 8
"If they each save $10 more." then
Eli will have: e + 10
Angela will have a + 10
"Eli will have saved $4 more than Angela's savings."
e + 10 = a + 10 + 4
This equation simplifies to: e = a + 4
We have a system of two equations in two variables.
e = a/3 + 8
e = a + 4
Since both equations are solved for e, we just equate the right sides.
a/3 + 8 = a + 4
Subtract a/3 from both sides. Subtract 4 from both sides.
a/3 - a/3 + 8 - 4 = a - a/3 + 4 - 4
4 = (2/3)a
Multiply both sides by 3/2
(3/2)4 = (3/2)(2/3)a
6 = a
a = 6
Angela has $6.
e = a + 4 = 6 + 4 = 10
Eli has $10.