72 - 55 = 17
(17/55) x 100
= 1700/55
= 30.90909...
= 30.9% (3sf)
(2) <em>x</em>
2<em>x</em> ⁴ means 2 × <em>x</em> ⁴ = 2 × <em>x</em> × <em>x</em> × <em>x</em> × <em>x</em>
<em />
(3) 3
-3⁴ means - (3 × 3 × 3 × 3)
(4) -2
(-2)⁵ means (-2) × (-2) × (-2) × (-2) × (-2)
(5) <em>y</em>
10<em>xy</em> ² means 10 × <em>x</em> × <em>y</em> × <em>y</em>
<em />
(6) <em>m</em>
5<em>m</em> ²<em>n</em> means 5 × <em>m</em> × <em>m</em> × <em>n</em>
[-2 3] times [2
1]
comes out to -2(2)+3(1) = -1. Eliminate the first answer choice, due to
the presence of that -7 instead of -1.
[-2 3] times [0
-3]
comes out to - 9. This matches answer choices #2, #3 and #4.
[3,-4][2
1]
comes out to 6-4, or 2. Matches #2, #3, #4.
[3, -4][0
-3]
comes out to +12, which matches answer choice #4.
Answer choice #4 is the correct one.
Review matrix multiplication if need be. Feel free to ask questions here and now if need be.