Dacă a=5 și b+c=6, să se afle:
a) 5a-10
b) 3b+3c
e) ab + ac
f) 3a +5. (20-3)
c) 2. (a+3) – 5 d) a+26+20
g) 26-3. (a+1) +4b +4c-2a
Răspunsuri la întrebare
Răspuns:
Explicație pas cu pas:
a = 5 si b + c = 6
a)
5 a - 10 = 5 × 5 - 10 = 25 - 10 = 15
b)
3b + 3c = 3 × ( b + c ) = 3 × 6 = 18
c)
2 × ( a + 3 ) - 5 = 2 × ( 5 + 3 ) - 5 = 2 × 8 - 5 = 16 - 5 = 11
d)
a + 26 + 20 = 5 + 46 = 51
e)
ab + ac = a × ( b + c ) = 5 × 6 = 30
f)
3a + 5 × ( 20 - 3) = 3 × 5 + 5 × 17 = 5 × ( 3+ 17) = 5 × 20 = 100
g)
26 - 3 × ( a + 1 ) + 4 b + 4 c - 2 a= 22
= 26 - 3 × ( 5 + 1 ) + 4 × ( b + c) - 2 × 5 =
= 26 - 3 × 6 + 4 × 6 - 10 =
= 26 - 18 + 24 - 10 =
= 32 - 10 =
= 22
a)5a -10
=5•5-10
=25-10
=15
b)3b+3c
=3(b+c)
=3•6
=18
e)ab+ac
=5b+5c
=5(b+c)
=5•6
=30
f)3a+5•(20-3)
=3•5+5•17
=15+85
=100
c)2•(a+3)-5
=2•(5+3)-5
=2•8-5
=16-5
=11
d)a+26+20
=5+26+20
=31+20
=51
g)26-3•(a+1)+4b+4c-2a
=26-3•(5+1)+4b+4c-2a
=26-3•6+4(b+c)-2•5
=26-18+4•6-10
=26-18+24-10
=8+24-10
=32-10
=22
MULT SUCCES!!!☺