Gaira was asked to evaluate the algebraic expression –3.8x + 6 when x = –7.5.

–3.8(–7.5) + 6(–7.5)

28.5 + (–45)

(–16.5)

What mistake did she make? What is the correct answer?

Sample response:

Gaira made a mistake when substituting the value –7.5 in for x. She multiplied both terms of the expression by –7.5 when she should have only multiplied –3.8 by –7.5. The correct answer is 34.5.

What is the lcm of 16 and 40 ? 24 and 40 ?

Credit card a offers an introductory apr of 3.4% for the first three months and standard apr of 15.7% thereafter,

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?