Question

3. Dacă x = 5 și a + b = 13, calculați: a) 3. X+7.a +7.b; c) 10.X +(4.a +4.b); b) x.a +x.b-50; d) (4.a +4.6-2.x). (2.a +2.6+x).​

Answer 1

a)

$3 \times 5 + 7 \times a + 7 \times b =$

$15 + 14 \times 13 =$

$182 + 15 = 197$

b)

$x \times a + x \times b - 50 =$

$5 \times a + 5 \times b - 50 =$

$10 \times 13 - 50 =$

$130 - 50 = 80$

c)

$10 \times x + (4 \times a + 4 \times b) =$

$10 \times 5 + (4 \times a + 4 \times b) =$

$50 + (8 \times 13) =$

$50 + 104 = 154$

d)

$(4 \times a + 4 \times 6 - 2 \times x) \times (2 \times a + 2 \times 6 + x) =$

$(4 \times a + 24 - 10) \times (2 \times a + 12 + 5) =$

$4 \times a + 24 -10 \times 2 \times a + 12 + 5 =$

$4 \times a + 24 - 20 \times a + 12 + 5 =$

$4 \times a + 4 \times a = 12 - 5$

$8 \times 2 \times a = 7$

$16 \times a = 7$

$a = 16 - 7$

$a = 9$

Sper că te-am fost de folos!!!