What's the addictive inverse of 4x - 5

Simplify the expression. 3 (a+b) + 6a-2b

When people say 8:15 times 195 equals 15x, what does 15x mean or stand for

What is the square root of 18

Factorise fully this expression 2x^2+x-15

The total cost in dollars to produce q units of a product is C (q). Fixed costs are $13000. The marginal cost is C' (q) = 0.006q^2-q+50. Estimate C (170), the total cost to produce 170 units. Find the value of C' (170).

A newspaper reporter wants to know how popular the hobby of bird watching is in the city. He asked people at the local bird refuge if they watched birds as a hobby. Which of the following best explains whether the reporters data is valid or not?

I am very confused on how to figure out if y = 3/4x is proportional?

Alison wants to buy a mountain bike for $339.12. If she saves $28.26 each month, in how many months will she be able to buy the bike?

At 12 o'clock the temperature was 7°C. The temperature decreased by - 20°C. What is the new temperature?

Ashleys rentals charges $27.50 per hour to rent a surfboard and a wetsuit. Darlas surf shop charges $23.25 per hour to rent a surfboard plus $17 extra for a wetsuit.