How would I answer 1.75 times 6

Can someone me with this problem i don't understand i need

Asphere has a diameter of 10 in. what is the volume of the sphere?

Follow these steps using the algebra tiles to solve the equation −5x + (−2) = −2x + 4. 1. add 5 positive x-tiles to both sides and create zero pairs. 2. add 4 negative unit tiles to both sides and create zero pairs. 3. divide the unit tiles evenly among the x-tiles. x =