How do I answer this wuestion?

-9/12 - (-7/4) =

Is x=-2 a solution of the equation 1-6x=7?

An antique vase was bought for $80 and was later sold for $240. Find the profit as a percentage of the cost price

At Least One Defective iPhone It has been reported that 20% of iPhones manufactured by Foxconn for a product launch did not meet Apple's quality standards. An engineer needs at least one defective iPhone so she can try to identify the problem (s).

The velocity of sound in air is given by the equation v = 20 √273 + where v is the velocity in meters per second and t is the temperature in degrees Celsius. Find the temperature when the velocity of sound in air is 369 meters per second.

In which step did Souta make the first error?

Quadratic equation : X^2+4x+4

What is the measure of a) 160 degrees b) 20 degrees c) 19 degrees d) 161 degrees

Find the distance (-1,2) (7,8)

Which of these is likely to be his next step in constructing the perpendicular line?

Fractions is greater than 2/5 and less than 3/5?