$7\cdot b\cdot (-3)=7\cdot (-3)\cdot b=-21b$

Коэффициент равен $-21$.

$-{\Large\frac{4}{5}}x\cdot \left(-{\Large\frac{25}{2}} y\right)=-{\Large\frac{4}{5}}\cdot \left(-{\Large\frac{25}{2}}\right)xy=10xy$

Коэффициент равен $10$.

$-12d+ d + 8d-16d=(-12+1+8-16)d=-19d$

$-{\Large\frac{1}{7}}t+{\Large\frac{12}{35}}t=\left(-{\Large\frac{1}{7}}+{\Large\frac{12}{35}}\right)t=\left(-{\Large\frac{5}{35}}+{\Large\frac{12}{35}}\right)t={\Large\frac{7}{35}}t={\Large\frac{1}{5}}t=0{,}2t$

$5{,}1f-7{,}9f+ 0{,}4f=(5{,}1-7{,}9+ 0{,}4)f=-2{,}4f$

$4(2s-1)+(-3-8s)=8s-4-3-8s=-7$

$-4(d - 3)-(-d+ 3)=-4d+12+d-3=-3d+9$

$2~(2{,}3x-1)-3~(0{,}2x+1)=4{,}6x-2-0{,}6x-3=4x-5$

При $x=-11$:

$4\cdot (-11)-5=-44-5=-49$