Will mark brainliest, 60 points

Answer:
[tex] \boxed{ \bold{ \sf{ \: 1. \: \: \: \: \: 198}}}[/tex]
[tex] \boxed{ \bold{ \sf{2. \: \: \: \: \: - 8}}}[/tex]
[tex] \boxed{ \bold{ \sf{ 3. \: \: \: \: \: \frac{64}{343} }}}[/tex]
Step-by-step explanation:
1. Given, u = 20 , x = 4 , y = 7 , z = 10
[tex] \sf{ \frac{u}{z} + x {y}^{2} }[/tex]
⇒[tex] \sf{ \frac{20}{10} + 4 \times {7}^{2} }[/tex]
⇒[tex] \sf{ \frac{20}{10} + 4 \times 49}[/tex]
⇒[tex] \sf{ \frac{20}{10} + 196}[/tex]
⇒[tex] \sf{ \frac{20 + 196 \times 10}{10} }[/tex]
⇒[tex] \sf{ \frac{20 + 1960}{10} }[/tex]
⇒[tex] \sf{ \frac{1980}{10} }[/tex]
⇒[tex] \sf{198}[/tex]
2. [tex] \sf{4( - 2)}[/tex]
Multiplying or dividing a positive integer by any negative integer gives a negative integer
= - 8
3. [tex] \sf{( \frac{4}{7} ) ^{3} }[/tex]
⇒[tex] \sf{( \frac{ {4}^{3} }{ {7}^{3} } })[/tex]
⇒[tex] \sf{ \frac{4 \times 4 \times 4 }{7 \times 7 \times 7}} [/tex]
⇒[tex] \sf{ \frac{64}{343} }[/tex]
Hope I helped!
Best regards! :D
Answer:
[tex]\Huge \boxed{\mathrm{18. \ \ \ 198}} \\\\\\ \Huge \boxed{\mathrm{19. \ \ \ -8}} \\\\\\ \Huge \boxed{\mathrm{20. \ \ \ \frac{64}{343} }}[/tex]
[tex]\rule[225]{225}{2}[/tex]
Step-by-step explanation:
[tex]\displaystyle \frac{u}{z} +xy^2[/tex]
u = 20, x = 4, y = 7, and z = 10.
[tex]\Rightarrow \displaystyle \frac{20}{10} +(4)(7)^2[/tex]
[tex]\Rightarrow \displaystyle 2+(4)(49)[/tex]
[tex]\Rightarrow 2+196[/tex]
[tex]\Rightarrow 198[/tex]
[tex]4(-2)[/tex]
Rewriting.
[tex]\Rightarrow -(4*2)[/tex]
Multiplying.
[tex]\Rightarrow -8[/tex]
[tex]\displaystyle ( \frac{4}{7} )^3[/tex]
Distributing the cube sign to the numerator and the denominator.
[tex]\Rightarrow \displaystyle \frac{4^3 }{7^3 }[/tex]
[tex]\Rightarrow \displaystyle \frac{64}{343}[/tex]
[tex]\rule[225]{225}{2}[/tex]