What is the slope of a line perpendicular to the line with equation y = 4x + 5

What can you determine about the solutions of this system

Find two numbers if their sum is 91 and the ratio is 6: 7?

Afamily has two cars. the first car has a fuel efficiency of 25 miles per gallon of gas and the second has a fuel efficiency of 15 miles per gallon of gas. during one particular week, the two cars went a combined total of 1025 miles, for a total gas consumption of 55 gallons. how many gallons were consumed by each of the two cars that week?