Answer:
because they add up to 90 and a right angle is 90 itself which would give you 180
What's the question you're asking
A simple way you could solve this is by drawing a tape graph.
Draw a long rectangular box.
Cut the box into 8 pieces, seeing as how 5/8 of the coins are dimes.
We have to take 48 and divide it by 8, we get 6, so now we know how many dimes are evenly split into each piece.
Now color in 5 pieces of the tape.
This represents the 5 in 5/8.
Now to find the number of coins, simply multiply 5 by 6, you get the answer of 30.
I hope this helps, if you are confused with any part of my explanation, ask and I will clarify.
STEPS:
-1-6X-6>-11-7X
GROUP LIKE TERMS
-6X-1-6>-11-7X
SUBTRACT THE NUMBERS:-1-6=-7
-6X-7>-11-7X
ADD SEVEN TO BOTH SIDES
-6X-7+7>-11+7-7X
SIMPLIFY
-6X>-7X-4
ADD 7X TO BOTH SIDES
-6X+7X>-7X+7X-4
SIMPLIFY
X>-4
SO THE ANSWER IS X>-4
I think the number would be 1.