True or false a system of equations including a line and a parabola can have only 2 solutions

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

What happens to the area as the sliders are adjusted? what do you think the formula for the area of a triangle is divided by 2?

After reading 80% of her e-mails in her inbox, danette still has m unread e-mails. which of the following expressions could represent the number of e-mails danette had in her inbox before she started reading? choose 2 answers: (choice a) 5m (choice b) 1.8m (choice c) 80m (choice d) m/0.8 (choice e) m/1−0.8