A door has an area of 21 square feet. It is 7 feet tall. How wide is the door?
1 answer:
You might be interested in
Answer:
errr polynomials ahaha
so basically we can multiply the power outside of the parantheses with the exponents on the inside:
so
this will give us:
-3x^8y^4
we also unfortunately, have to use the power on the coefficient -3 as well and we cant just MULTIPLY -3 by 4, we are going to have to multiply -3 with -3 4 TIMES(anytime we see a coefficient we MUST multiply the coefficient by itself according to the number outside of the parantheses)
so:
-3*-3*-3*-3=81
final expression
<u>Let's solve this problem step-by-step</u>
<u>Let's set</u>:
2x + 6y = 36 -- equation 1
x + 4y = 20 -- equation 2
(equation 2) * 2
2x + 8y = 40 -- equation 3
(equation 3) - (equation 1)
2y = 4
y = 2 -- equation 4
Plug (equation 4)'s value of y into (equation 2)
x + 4(2) = 20
x = 20 - 8
x = 12
<u>Thus x = 12 and y = 2</u>
<u>Let's check, by substituting these values</u>
<u>Answer: x = 12 and y = 2</u>
Hope that helps!