Answer:
x as a fraction 7
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x as a decimal: 7.5
Explanation:
2.5x - 6.4 + 1.2x = 21.35
Combine 2.5x and 1.2x to get 3.7x.
3.7x - 6.4 = 21.35
Add 6.4 to both sides.
3.7x = 21.35 + 6.4
Add 21.35 and 6.4 to get 27.75.
3.7x = 27.75
Divide both sides by 3.7.
x =

Expand
by multiplying both numerator and the denominator by 100.
x =

Reduce the fraction
to lowest terms by extracting and canceling out 185.
x =

simplify
7
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Hope it helps and have a great day! =D
~sunshine~