180+x=7x because the father plus the daughter is equal to 7 times her weight which is x?
X% of 4 = x*4/100 = 0.04x
y% of 5 = x*5/100 = 0.05y
x% of 4 + y% of 5 = 0.04x + 0.05y
How you express a number, n, as percentage of 11?: [n/11]*100= 9.10n %
Then make n = 0.04x + 0.05y
9.10n %= 9.10[0.04x + 0.05y] %= (0.3656x + 0.455y)%
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