What is the answer for 5.2 × 10-9 + 3.1 × 10-8 = × 10?

In a school 2/3 of the students study a language of those who study a language 2/5 study french

Which of the following is true about the graph of f(x)=7^x. select all that apply. a= it intercepts the x axis b=it intercepts both axis c=it intercepts neither d=it intercepts the y axis

I'm confused on this could anyone me and show me what i need to do to solve it.