Let x = the width
then
2x = the length
:
The box dimensions: 2x by x by 4
Given the surface area:
2(2x*x) + 2(2x*4) + 2(x*4) = 220
:
4x^2 + 16x + 8x = 220
A quadratic equation:
4x^2 + 24x - 220 = 0
simplify, divide by 4
x^2 + 6x - 55 = 0
Factor
(x+11)(x-5) = 0
The positive solution is what we want here:
x = 5 ft is the width
then
2(5) = 10 ft is the length
:
Find the volume
10 * 5 * 4 = 200 cu/ft is the volume
Answer:


Step-by-step explanation:
Let
. We have that
if and only if we can find scalars
such that
. This can be translated to the following equations:
1. 
2.
3. 
Which is a system of 3 equations a 2 variables. We can take two of this equations, find the solutions for
and check if the third equationd is fulfilled.
Case (2,6,6)
Using equations 1 and 2 we get


whose unique solutions are
, but note that for this values, the third equation doesn't hold (3+2 = 5
6). So this vector is not in the generated space of u and v.
Case (-9,-2,5)
Using equations 1 and 2 we get


whose unique solutions are
. Note that in this case, the third equation holds, since 3(3)+2(-2)=5. So this vector is in the generated space of u and v.
Answer: -3 ≤ x ≤ -1
Step-by-step explanation:
1 ≤ 3 - 4x ≤ 9
1 + 3 ≤ - 4x ≤ 9 + 3; Add 3 on all sides
4 ≤ -4x ≤ 12
1 ≤ -x ≤ 3; Divide 4 on all sides
-1 ≥ x ≥ -3; Multiply -1 on all sides(FYI: When multiplying or dividing negative numbers in inequalities, make sure to reverse the signs as well)
It’s B. because 6•6=36 and B shows a little over six so B would be your answer.