Can you tell me if this equation I made for a project is correct? x-13=7

x-13+13=7+13

x=20

Can you help me fix it if it is not correct?

THANK YOU

Which of the following quartic functions has x = –1 and x = –2 as its only two real zeroes?

Data from 2005 for various age groups show that for each $100 increase in the median weekly income for whites, the median weekly income of blacks increases by $105. also, for workers of ages 25 to 54 the median weekly income for whites was $676 and for blacks was $527. (a) let w represent the median weekly income for whites and b the median weekly income for blacks, and write the equation of the line that gives b as a linear function of w. b = (b) when the median weekly income for whites is $760, what does the equation in (a) predict for the median weekly income for blacks?

What percent of 18 is 24? and plz explain thx.