300-78:х=287
78/х=300-287
78/х=13
х=78/13
<span>х=6</span>
А)6729
б)8061
в)15418
г)8003806
д)5700030
е)7400052
-1,25*8*4= - 40
(8-3/7)*(-7)=53/7*(-7)= -53
0,25*(-7)*4= - 7
(-8 цел. 1/3 - 2/3) / 3=(-27/3) / 3 = -27
(2/7+1/9)*(-7)=25/63 *(-7) = -225
3 цел. 1/3 * 1/2 *(-3) = 5/3*(-3)= -5
9m²-12mn=3m(3m-4n)
15x^6-5x⁴=5x⁴(3x²-1)
ax-ay+7x-7y=a(x-y)+7(x-y)=(x-y)(a+7)