Question

Daca x=5 si a+b=13, calculati:
a) 3 · x +7 · a+7 · b
b) 10 · x -(4 ·a + 4 · b)
c) xa +xb-50
d) (4a+4b-2x)·(2a+2b+x)
AJUTATI-MA!!!!!!!!!!!!!!!1

Answer 1

x = 5
a + b = 13

a) 3 • x + 7 • a + 7 • b =
3 • 5 + 7 • ( a + b ) =
15 + 7 •13 = 15 + 91 = 106.

b) 10 • x - ( 4 • a + 4 • b ) =
10 • 5 - [ 4 • ( a + b ) ] =
50 - 4 • 13 = 50 - 52 = -2.

c) xa + xb - 50 =
x • ( a + b ) - 50 =
5 • 13 - 50 = 65 - 50 = 15.

d) ( 4a + 4b - 2x ) • ( 2a + 2b + x ) =
[ 4 • ( a + b ) - 2 • 5 ] • [ 2 • ( a + b ) + x ] =
( 4 • 13 - 10 ) • ( 2 • 13 + 5 ) =
( 52 - 10 ) • ( 26 + 5 ) =
42 • 31 = 1302.


Sper că te-am ajutat :)