Answer: 35 seventh graders
Step-by-step explanation:
The simplified ratio is 4:7 sixth graders to seventh graders
The number of sixth-graders is 5 times the number shown in the ratio of attendees (20/4 = 5). Thus, the number of 7th graders must also be 5 times greater than the simplified ratio.
7*5 = 35, thus there are 35 seventh graders in the club
A is the answer to the question
Answer:
Part A: 140
Step-by-step explanation:
Line ACE is a straight line meaning it equals 18 degrees. To find out what Angle CEF is you have to subtract 40 from 180. That gives you 140 degrees.
Hope its helpful!

where det(<em>A</em>) = 1×1 - 2×1 = -1.

where det(<em>B</em>) = 0×2 - (-1)×1 = 1. Then

On the other side, we have

and det(<em>AB</em>) = det(<em>A</em>) det(<em>B</em>) = (-1)×1 = -1. So

and both matrices are clearly the same.
More generally, we have by definition of inverse,

where
is the identity matrix. Multiply on the left by <em>A </em>⁻¹ to get

Multiplication of matrices is associative, so we can regroup terms as

Now multiply again on the left by <em>B</em> ⁻¹ and do the same thing:
