Find a ratio equal to radio give 90: 18?

30:6 is an equivalent ratio. Anymore and you would have a decimal. 

Volume is length times width times height so
20 times 8 times 30 which is 4,800
surface area is ph (p is perimeter of base), h is height.
so perimeter would be length+length+width+width so 20+20+8+8 which is 56. so multiply 56 times 30 which is 1680. hope this !

Let us take option c(-3x + 6i)(x + 2i)-3x² - 6xi + 6xi + 12i²-3x² + 12i²we know that i² = -1-3x² - 12option c is the answer