Rewrite the system of equations in matrix form.

This system has a unique solution
so long as the inverse of the coefficient matrix
exists. This is the case if the determinant is not zero.
We have

so the inverse, and hence a unique solution to the system of equations, exists as long as m ≠ -4.
The number of ounces of cereal in the third box is 32.
<u>Explanation:</u>
Given-
10 oy box = $3
Price of 1 ounce box = $3/10
= $0.3
20 oy box = $5
Price of 1 oy box = $5/20
= $0.25
Therefore, it is beneficial to buy a 20 oy box as it is comparatively cheaper than the 10 oy box.
Third box of cereal = $8
$5 is the price of 20 oy box
$8 will be the price of x oy box
So,

Therefore, the number of ounces of cereal in the third box is 32.
ANSWER: 46.8
39% of 120
The word "of" means multiplied. So you will have to multiply 39% x 120
To do that, first step is to change the percent (39%) into a decimal
39% = 0.39 (You move the decimal twice to the left, not right)
There's an invisible decimal behind 9 so ALWAYS move it twice.
= 39(.)⇒ 0.39
Then your final step is to multiply
120 x 0.39
1 2 0
x 0 . 3 9 ← notice this decimal
_______ ∨
1 0 8 0 ∨
+ 3 6 0 0 ∨
_______ ∨
4 6 8 0 There's an invisible decimal before the 0. Move that decimal two times to the left. 4680(.)⇒ 46.8
<span> 3h2 • (h + 7) • (h + 1) is the simplified version.</span>