What is the value of a, if the graphs of 3y + x = 0 and 4y + ax + 3 = 0 are to meet at a right angle?

a = -12

Step-by-step explanation:

For two lines to meet at a right angle, they are perpendicular to each other. Therefore the product of the slopes of the two lines is -1.

The slope of 3y + x = 0 will be -1/3 (rearrange the terms, 3y = -x and therefore y = -1/3 x).

The slope of 4y + ax + 3 = 0 will be -a/4. (4y = -ax - 3, therefore y = -a/4 x - 3/4)

Since the product of the slopes is -1, we can set up an equation now.

-1/3 * -a/4 = -1

a/12 = -1

a = -12

b.) 160 miles on a 5 gallons car

step-by-step explanation:

240/10=24 miles/gallon

160/5=32 miles/gallon

30/1=30 miles/gallon

168/6= 28 miles/gallon

32 miles/gallon is the most amount, so this is the best.