Solve each problem.
21.A jar contains only pennies, nickels, and dimes. The number of dimes is one more than
the number of nickels, and the number of pennies is six more than the number of nickels.
How many of each denomination are in the jar, if the total value is $4.80?
22.Two angles of a triangle have the same measure. The measure
of the third angle is 4° less than twice the measure of each of
the equal angles. Find the measures of the three angles.262 CHAPTER 4 Systems of Linear Equations
Measures are in degrees.2 x – 4xxIn Exercises 23–27, point A has coordinates and point B has coordinates.
23.What is the equation of the horizontal line through A?
24.What is the equation of the vertical line through B?
25.What is the slope of line AB?
26.What is the slope of a line perpendicular to line AB?
27.What is the standard form of the equation of line AB?
28.Graph the line having slope and passing through the point.
29.Graph the inequality.
30.Given that , find (a) and (b).Solve by any method.ƒ 1 x 2 =x^2 + 3 x- 6 ƒ 1 - 32 ƒ 1 a 2- 3 x- 2 y... 6
(^231) - 1, - 32
1 - 2, 6 2 1 4, - 22
31.
4 x- y= 15- 2 x+ 3 y=- 15 32.
2 x- 6 y= 14
x- 3 y= 7 33.- x+y-z=- 4
x-y-z= 0x+y+z= 1034.Ten years after the original Tickle Me Elmo became a
must-have toy, a new version, called T.M.X., was re-
leased in the fall of 2006. The original Tickle Me
Elmo’s average cost was $12.37 less than the recom-
mended cost of T.M.X., and one of each cost $67.63.
Find the average cost of Tickle Me Elmo and the rec-
ommended cost of T.M.X. (Source:NPD Group, Inc.;
USA Today.)35.The graph shows a company’s costs to pro-
duce computer parts and the revenue from
the sale of computer parts.
(a)At what production level does the cost
equal the revenue? What is the revenue
at that point?
(b)Profit is revenue less cost. Estimate the
profit on the sale of 1100 parts.Number of Parts (in hundreds)Dollars0123456789101000200030004000xyCostRevenueComputer Parts