[math]\frac{2}{5}t=6[/math]

[math]-4.5=a-8[/math]

[math]\frac{1}{2}+p=-3[/math]

[math]12=x\cdot3[/math]

[math]-12=-3y[/math]

[math]5x=0.4[/math]

[math]\frac{x}{5}=8[/math]

[math]3=\frac{-x}{5}[/math]

[math]7=-5x[/math]

[size=150]Evaluate each the expression if [math]x[/math] is [math]\frac{2}{5}[/math], [math]y[/math] is [math]-4[/math], and [math]z[/math] is [math]-0.2[/math].[/size][br][math]x+y[/math]

[math]2x-z[/math]

[math]x+y+z[/math]

[math]y\cdot x[/math]

Write an equation where a number is added to a variable, and a solution is -8.

Write an equation where a number is multiplied by a variable, and a solution is [math]\frac{-4}{5}[/math].

DeepSea Challenger’s descent was a change in depth of [math]\left(-4\right)[/math] feet per second. We can use the equation [math]y=-4x[/math] to model this relationship, where [math]y[/math] is the depth and [math]x[/math] is the time in seconds that have passed. How many seconds does this model suggest it would take for DeepSea Challenger to reach the bottom?

To end the mission DeepSea Challenger made a one-hour ascent to the surface. How many seconds is this?

The ascent can be modeled by a different proportional relationship [math]y=kx[/math]. What is the value of k in this case?