2x+4=10
2x=6
x=3
2(3)+4= 10
(plus, on parallelograms like that, parallel sides are equal to each other)
Answer:
A
Step-by-step explanation:
A. Here is why:
In a function, each x maps to exactly one value of y.
In B and C, x = -3 maps to both -1 and 2, is they are not functions.
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
