Question

dca a =14,iar b+c=25aflati valoarea expresiilor a+b+c .
a+3×b+3×c.
5×a+2×c+2×b.
a×b+a×c+5×a-16×b-16×c.

Answer 1

avem:
a = 14
b+c = 25

atunci:
a+b+c = 14+25 = 39

a+3×b+3×c = a+3×(b+c) = 14+3×25 = 14+75 = 89

5×a+2×c+2×b = 5×14+2×(c+b) = 70 + 2×25 = 70+50 = 120

a×b+a×c+5×a-16×b-16×c =
a×(b+c) + 5×14 - 16×(b+c) =
= 14×25 + 70 - 16×25 =
= 350 + 70 - 400 =
= 420 - 400 =
= 20