Question

Answer 1

\(a,\dfrac{x}{5}=\dfrac{16}{40}\Rightarrow x.40=5.16=80\\ \Rightarrow x=80:40\\ \Rightarrow x=2\\ b,\dfrac{y}{25}=\dfrac{-2}{5}\Rightarrow y.5=25.\left(-2\right)=-50\\ \Rightarrow x=-10\\ c,\dfrac{x}{7}=\dfrac{6}{21}\Rightarrow x.21=7.6=42\\ \Rightarrow x=2\)

Answer 2

a) x=2
b) y=-10
c) x=2
d) x=12; y=5
e) x=3; y=-15
f) x=8; y=-6
g) x=-4; y=6; z=8
h) x=\(\pm\)10
k) x=\(\dfrac{3}{2}\)

Answer 3

a) x=2
b) y=-10
c) x=2
d) x=12; y=5
e) x=3; y=-15
f) x=8; y=-6
g) x=-4; y=6; z=8
h) x=10