Answer:
first one
Step-by-step explanation:
a + b = c
subtract a from both sides
b = c - a
or
c - a = b
Answer: 2
Step-by-step explanation:
Expand the following:
(5 a + b/5)^2
(5 a + b/5) (5 a + b/5) = (5 a) (5 a) + (5 a) (b/5) + (b/5) (5 a) + (b/5) (b/5):
5×5 a a + (5 a b)/5 + (5 b a)/5 + (b b)/(5×5)
(5 a b)/5 = 5/5×a b = a b:
5×5 a a + a b + (5 b a)/5 + (b b)/(5×5)
(b×5 a)/5 = 5/5×b a = b a:
5×5 a a + a b + b a + (b b)/(5×5)
Combine powers. (b b)/(5×5) = (b^(1 + 1))/(5×5):
5×5 a a + a b + b a + (b^(1 + 1))/(5×5)
1 + 1 = 2:
5×5 a a + a b + b a + (b^2/5)/5
5 a×5 a = 5×5 a^2:
5×5 a^2 + a b + b a + (b^2/5)/5
5×5 = 25:
Answer: 25 a^2 + a b + b a + (b^2/5)/5
Step-by-step explanation:
Substitute the y in the 1st equation with the 2nd equation.
7x + 10(2x + 9) = 36
7x + 20x + 90 = 36
27x + 90 = 36
3x + 10 = 4
3x = -6
x = -2
So now we can find y.
y = 2x + 9 = 2(-2) + 9 = (-4) + 9 = 5.
So x = -2, y = 5.
