Answer:
x^2 -81
Step-by-step explanation:
(x+9)(x-9)
FOIL
first x*x = x^2
outer -9x
inner 9x
last -9*9 = -81
Add them together
x^2 -9x+9x -81
Combine like terms
x^2 -81
Answer:
4 boys, 3 girls
Step-by-step explanation:
brothers of John ⇒ x
sisters of John ⇒ y
John has as many brothers as sisters:
- x = y
brothers of Emily ⇒ x + 1 (Emily have the same amount of brother as John, plus one (John))
sisters of Emily ⇒ y -1 (Emily have the same amount of sister as John, minus one (herself))
Emily has twice as many brothers as sisters:
- 2 (y-1) = x+ 1
Now we have a system of 2 equations and 2 variables
x=y (I)
2y - 2 = x + 1 (II)
____________
Replace x in equation II
2y - 2 = y + 1
2y - y = 2 + 1
y = 3
____________
Replace y in equation I
x = y = 3
That mean that John have 3 brothers plus himself, there is 4 boys in the family and John have 3 sister, so there is 3 girls in the family
Answer:
No, because the two shorter sides added must be longer than the longest side.
Also 1 squared plus 2 squared is not equal to 5 squared.
You want to subtract 32.4 from 62 to get the value of t.
62- 32.4= 29.6