Răspuns :
a). 14a+21b=7(2a+3b);
b). 7a-28=7(a-4);
c). 21x+14y+7=7(3x+2y+1);
d). 7x+14y-35=7(x+2y-5);
e). 21xy-35z+14=7(3xy-5z+2);
b). 7a-28=7(a-4);
c). 21x+14y+7=7(3x+2y+1);
d). 7x+14y-35=7(x+2y-5);
e). 21xy-35z+14=7(3xy-5z+2);
a) 2×7a+3×7a=7(2a+3a)=7×5a
b) 7a-7×4=7(a-4)
c) 7×3X+2×7Y+7=7(3X+2Y+1)
d) 7X+2×7Y-5×7=7(X+2Y-5)
e) 3×7XY-5×7Z+2×7=7(3XY-5Z+2)
b) 7a-7×4=7(a-4)
c) 7×3X+2×7Y+7=7(3X+2Y+1)
d) 7X+2×7Y-5×7=7(X+2Y-5)
e) 3×7XY-5×7Z+2×7=7(3XY-5Z+2)