20/25 as a decimal is 0.8
Answer:
(x, y) = (- 2, 5)
Step-by-step explanation:
given the 2 equations
3y = 11 - 2x → (1)
3x = y - 11 → (2)
Rearrange (2) expressing y in terms of x
add 11 to both sides
y = 3x + 11 → (3)
Substitute y = 3x + 11 into (1)
3(3x + 11) = 11 - 2x
9x + 33 = 11 - 2x ( add 2x to both sides )
11x + 33 = 11 ( subtract 33 from both sides )
11x = - 22 ( divide both sides by 11 )
x = - 2
Substitute x = - 2 in (3) for corresponding value of y
y = (3 × - 2) + 11 = - 6 + 11 = 5
As a check
substitute x = - 2, y = 5 into (1) and (2) and if the left side equals the right side then these values are the solution.
(1) : left side = (3 × 5) = 15
right side = 11 - (2 × - 2) = 11 + 4 = 15 ⇒ left = right
(2) : left side = (3 × - 2 ) = - 6
right side = 5 - 11 = - 6 ⇒ left = right
solution = (- 2, 5 )
Use the equation
A= 2(wl +hl +hw)
Where
w is width
h is height
l is length
Answer:
-5 =x
Step-by-step explanation:
3^(x-1) = 9^(x+2)
Replace 9 with 3^2
3^(x-1) = 3^2^(x+2)
We know that a power to a power means the powers are multiplied
a^b^c = a^(b*c)
3^(x-1) = 3^(2x+2)
When the bases are the same, the powers have to be the same
x-1 = 2x+4
Subtract x from each side
x-x-1 =2x-x+4
-1 =x+4
Subtract 4 from each side
-1-4 =x+4-4
-1-4 = x
-5 =x