What is 5(a-5b)(a+b)​

Will give brainliest series to sigma notation write the following series in sigma notation. 6+10+14+18+22+26+30 example image shown below.

Find the quotient. 50a2 – 98b2 -5a +7b

Which of the expressions (on the photo document i inserted) together represent all solutions to the following equation? 8cos(12x)+4=-4 *the answer should be in degrees.* > i would like for someone to explain the process to find the solutions for this.