Question

Stiind ca x=14,calculati a+b in fiecare din cazurile
a)a+b-3x=56
b)7*a+7*b+7*x=700
c)39*a+39*b-39*x=3900
d)x*a+x*b=140
e)11*a+11*b+56+x=1170
f)30*x-a-b=241
g)9*x-2a-2*b=100
h)x*a+x*b+6*a+6*b=200

Answer 1

a) a+b-3*14=56 => a+b = 56-42 = 14
b) 7*a+7*b+7*14=700 => 7(a+b) = 602 => a+b = 86
c) 39*a+39*b-39*14=3900 => 39(a+b) = 3354 => a+b = 86
d) 14*a+14*b=140 => 14(a+b) = 140 => a+b = 10
e) 11*a+11*b+56+14=1170 => 11(a+b) = 1100 => a+b = 100
f) 30*14-a-b=241 <=> 420-(a+b)=241 = a+b = 179
g) 9*14-2*a-2*b=100 <=> 126- 2(a-b)=100 => 2(a-b) = 26 => a-b = 13
h) 14*a+14*b+6*a+6*b=200 <=> 14(a+b) + 6(a+b) = 200 <=> (a+b)(14+6)=200 => a+b=10

Sper ca te-am ajutat! :)