Complementary angles add up to 90 degrees.
So to find A you would need to add A and B together and equal it to 90 (3x+25+5x-7=90)
Combine like terms together (8x+18=90)
Subtract 18 from night sides (8x=72)
Divide by 8 on both sides (x=9)
Then to find A substitute x into its equation (3(9)+25)=(27+25)=52

A=52 I think

7 0

3 years ago

Make t the subject of k= t-e/2

Sophie [7]

Answer:

$t=k+\frac{e}{2}$

Step-by-step explanation:

$k=t-\frac{e}{2}\\t=k+\frac{e}{2}$

5 0

3 years ago

57 is the same as g and 231

vesna_86 [32]

57 is the same as g and 231.

We could also say that 57 is equal to g and 231.

57= g + 231

I hope this helps!
~kaikers

6 0

3 years ago

The mean of the scores obtained by a class of students on a physics test is 42. The standard deviation is 8%. Students have to s

NemiM [27]

The correct answer is:
16%.

Explanation: 
We use a z-score to answer this question.
The formula for a z-score is:
z= $\frac{x-mue}{sigma}$ ,
where mue is the mean and sigma is the standard deviation.

Using our information, we have:
z= $\frac{50-42}{8} = \frac{8}{8} = 1$ .

Using a z-table, we see that the area to the left of, or less than, this score is 0.8413. We want to know how many students scored more than this, so we subtract from 1:
1-0.8413=0.1587, which rounds to 16%.

7 0

3 years ago

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