21y+7x=56? what is the value of X

Multiplying an even number of negative numbers gives an answer that is choose from:

The label on the car's antifreeze container claims to protect the car between ? 40°c and 125°c. to convert celsius temperature to fahrenheit temperature, the formula is c = 5 over 9 (f ? 32). write and solve the inequality to determine the fahrenheit temperature range at which this antifreeze protects the car. ? 40 > 5 over 9 (f ? 32) > 125; ? 40 > f > 257 ? 40 < 5 over 9 (f ? 32) < 125; ? 40 < f < 257 ? 40 < 5 over 9 (f ? 32); ? 40 < f 5 over 9 (f ? 32) < 125; f < 257

Complete the solution of the equation. find the value of y when x equals -5. -4x - 8y = -52