Question

2.Calculati produsul dintre suma si diferenta nr 206,13 si 107,2.
3 Calculati 2a +2b si 5a + 7b+ 2c , stind ca a+b =17,25 si b+c=2,4

Answer 1

1) (206,13+107,2) x (206,13-107,2)=313,33 x 98,93=30997,7

2) 2a+2b=2(a+b)=2x17,25=34,5
a+b=17,25 I x5
b+c=2,4 I x2
5a+5b+2b+2c=86,25+4,8
5a+7b+2c=91,05