Question

daca x=5 si a+b=13 calculati:10× x+(4×a+4×4) ; (4×a+4×b-2×x)× (2×a+2×b+ x)

Answer 1

x = 5    si    a + b = 13

10 x + ( 4 a + 4 b ) = 10 × 5 + 4 × 13 = 50 + 52 = 102

( 4 a + 4 b - 2 x ) × ( 2 a + 2 b + x ) = 1 302

= [ 4 × ( a + b ) - 2 × 5 ] × [ 2 × ( a + b ) + 5 ] =

= ( 4 × 13 - 10 ) × ( 2 × 13 + 5 ) =

= ( 52 - 10 ) × ( 26 + 5 ) =

= 42 × 31 =

= 1 302