40 POINTS FOR THIS ALGEBRA WORD PROBLEM
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Answer:
9
Step-by-step explanation:
let the number
=
x
then 4 times the number
=
4
x
and 4 times the number increased by 15
=
4
x
+
15
also 6 times the number
=
6
x
and 3 less than 6 times the number
=
6
x
−
3
equating the two expressions gives the equation
4
x
+
15
=
6
x
−
3
←
solve for x
subtract 6x from both sides
4
x
−
6
x
+
15
=
6
x
−
6
x
−
3
⇒
−
2
x
+
15
=
−
3
subtract 15 from both sides
−
2
x
+
15
−
15
=
−
3
−
15
⇒
−
2
x
=
−
18
divide both sides by
−
2
−
2
x
−
2
=
−
18
−
2
⇒
x
=
9
As a check
(
4
×
9
)
+
15
=
36
+
15
=
51
(
6
×
9
)
−
3
=
54
−
3
=
51
⇒
the number is 9