15x7=105 years
9x5=45 years for the boys
105-45=60 so 60years girls
60/6=10 60 years divided by the 6 girls
Mean is 10 years for girls
Answer:
it is basically 10*10=100
Step-by-step explanation:
대답:
답은 다섯 번째입니다. 이 답변이 당신에게 맞기를 바랍니다.
4a + 6b = 10
2a - 4b = 12...multiply by -2
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4a + 6b = 10
-4a + 8b = - 24 (result of multiplying by -2)
------------------add
14b = - 14
b = -14/14
b = -1
2a - 4b = 12
2a - 4(-1) = 12
2a + 4 = 12
2a = 12 - 4
2a = 8
a = 8/2
a = 4
so 12a = 12(4) = 48 <==
hi
f(a+7)
f(x) =x²+5
by remplacing X by (a+7) :
then f(a+7) = (a+7)²+5
= a² +2*a*7 +49 +5
= a² +14a +54
