( x + 4), (x - 9) = 4x
Hope this helps!
It will take her 45 minutes to run 5 miles,because 27/3=9 and 9•5=45
Answer:
= 29/12 − -13/6
<span>= ((29 × 6) − (-13 × 12)) / (12 × 6) </span>
= (174 - -156) / 72
= 330/72
= 55/12
<span>= 4 7/12</span>
Answer:
The answer to your question is car 1 = 30 gal and car 1 = 20 gal
Step-by-step explanation:
car 1 = a
car 2 = b
Efficiency of car 1 = 35 mi/gal
Efficiency for car 2 = 20 mi/gal
Total distance = 1450
Total gas consumption = 50 gal
Equations
35a + 20b = 1450 ------- (I)
a + b = 50 ------- (II)
Solve by elimination
Multiply equation II by -35
35a + 20b = 1450
-35a - 35b = -1750
Simplify
0 - 15b = -300
Solve for b
b = -300/-15
Result
b = 20
Substitute b in equation II to find a
a + 20 = 50
Solve for a
a = 50 -20
Result
a = 30
Answer:
45
Step-by-step explanation:
AEF is a similar triangle to ABC. that means it has the same angles, and the sides (and all other lines in the triangle) are scaled from the ABC length to the AEF length by the same factor f.
now, what is f ?
we know this from the relation of AC to FA.
FA = 12 mm
AC = 12 + 28 = 40 mm
so, going from AC to FA we multiply AC by f so that
AC × f = FA
40 × f = 12
f = 12/40 = 3/10
all other sides, heights, ... if ABC translate to their smaller counterparts in AEF by that multiplication with f (= 3/10).
the area of a triangle is
baseline × height / 2
aABC = 500
and because of the similarity we don't need to calculate the side and height in absolute numbers. we can use the relative sizes by referring to the original dimensions and the scaling factor f.
baseline small = baseline large × f
height small = height large × f
we know that
baseline large × height large / 2 = 500
baseline large × height large = 1000
aAEF = baseline small × height small / 2 =
= baseline large × f × height large × f / 2 =
= baseline large × height large × f² / 2 =
= 1000 × f² / 2 = 500 × f² = 500 ×(3/10)² =
= 500 × 9/100 = 5 × 9 = 45 mm²
