Question

A-B=18 A:B is equivalent to 11:5

Answer 1

One way is to use brute force (find bigger equivalent ratios and add them)
11:5
to make them bigger, we multiply both by the same number 
11:5
11+5=16 nope
11:5 times 5 to both=55:25
add 
55+25=80
we can just add the numbers before multiplying and then multiply after

11+5=16
16 times what=18
divide both sides by 16
1.125=what
we need to multiply each by 1.125
11:5 times 1.125 to both =12.375 : 5.625
12.375+5.625=18

a=12.375
b=5.625

Hope this helps :)

Answer 2

Answer:

A= 33 and B = 18

Step-by-step explanation:

To find the value of A and B, we need to take into account the proportion A: B that is equal to 11:5. We can multiply both quantities of this proportion by some number to find two values that satisfy A - B = 18.

The simplest case would be to think A = 11 and B = 5, but 11-5 is not equal to 18 ⇒ 11 - 5 = 6  which does not satisfy A - B = 18.

Another option to find an answer is to multiply the ratio by two: 2 (11: 5) = 22:10, but it turns out that is A = 22 and B = 10 ⇒22-10 is not equal to 18 either.

Thus we arrive at the one that is the correct answer, multiplying the proportion by three: 3 (11: 5) = 33 - 15, and in this case we would have A = 33 and B = 15, which meets the condition A - B = 18, because 33 - 15 = 18