Question

tap hop cac phan tu a la BC(12,15,18) va 150<a<400

Answer 1

12 = 2².3; 15 = 3.5; 18 = 2.3²

=> BCNN(12, 15, 18) = 2².5.3² = 180

=> a \(\in\)BC(12, 15, 18)=B(180)={0; 180; 360; 540; ...}

Mà 150 < a < 400

=> a \(\in\){180 ; 360}.

Answer 2

12= 2²x3      ;       15 = 3x5      ;      18 = 2 x 3²

BCNN(12;15;18) = 2²x3²x5 = 180

BC(12;15;18)=B(180) = {0;180;360;540;......}

mà 150<a<400

=> a = {180;360}