Take the unknown number as 'y'.
=》33% = 33/100
=》1.45 = 145/100
33/100 × y = 1.45
33/100 × y = 145/100
33y = 145/100 × 100/1
33y = 145
y = 145/33
y = 4.39
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RainbowSalt2222 ☔
If you could send an image that is clearer I will be able to help you more, but for what we have: 3y+13=5y-5, the answer would be 2y=18 (after doing all your algebra). Then you would divide both sides by 2 and get y=9. After this you can plug in 9 for every y and find the angles/measures of all sides!
Hope this helped, and if you need any further assistance, please let me know!
If we call the number "x" then:
x*25%=21
x*25/100=21
x=21*4
x=84
We are asked to simplify the expression

,
what we do is, we form a single fraction where the numerator is the product of the numerators, and the denominator is the product of the denominators, that is:

simplify the common numbers and terms in the numerator and denominator:

Answer: