Răspuns :
[tex]c \times (a + b) + d \times (a + b) = (c + d) \times (a + b) = 27 \times 30 = 810[/tex]
ac + bc + ad + bd = 810
= c × ( a + b ) + d × ( a + b ) =
= ( a + b ) ( c + d ) =
= 27 × 30 =
= 810
ac + bc + ad + bd = 810
= c × ( a + b ) + d × ( a + b ) =
= ( a + b ) ( c + d ) =
= 27 × 30 =
= 810