Answer:

Step-by-step explanation:
Recall what the relationship between cosine and secant:

In other words, secant is the reciprocal of cosine.
So, if we know cosine, we only need to find its reciprocal to find secant.
We are given that cosine is:

Then secant must be:

So:

Square:

And we're done!
In order to get the common denominator when adding fractions or subtracting fractions, you have to make sure that the denominator of the two items are divisible by each other. In this case, 9 is not divisible by any of the given denominators which is 4 and 5. So in this case, the common denominator will have to be 20. 5 x 4 will equal to 20 and you will also multiply 3 x 5 to get the new numerator. After that, you will multiply 2 x 4 to get the new numerator of the other fraction. The new fractions will be 15/20 and 8/20. From there, you can add or subtract
Answer:
a = 8
b ≠ 18
Step-by-step explanation:
y = 4x - 7
2y = ax + b
For there to be no solution, the lines (if graphed) should be parallel meaning that their slopes are equal but the y-intercepts are different
y = mx +b is the equation of a line where m is the slope and b is the y-intercept
Multiply the first equation by 2
2y = 8x - 14
2y = ax + b
So a has to equal 8
b can be anything except 14 (otherwise the lines would be the same)
Hope this answers your question :)
102/159 = x/4
34/53 = x/4
34(4) = x(53)
136 = 53x
136/53 = x