An inequality that represents his purchase is 0.85x + 1.29y < 5. The sign is less than, because you spend less than that, not equal to that.
First, we can expand the terms on the right side of the equation:
y
−
10
=
2
(
x
−
8
)
y
−
10
=
(
2
×
x
)
−
(
2
×
8
)
y
−
10
=
2
x
−
16
Next, we can add
10
and subtract
2
x
from each side of the equation:
−
2
x
+
y
−
10
+
10
=
−
2
x
+
2
x
−
16
+
10
−
2
x
+
y
−
0
=
0
−
6
−
2
x
+
y
=
−
6
Now, multiply each side of the equation by
−
1
−
1
(
−
2
x
+
y
)
=
−
1
×
−
6
(
−
1
×
−
2
x
)
+
(
−
1
×
y
)
=
6
2
x
+
(
−
y
)
=
6
or
2
x
−
y
=
6
The Answer is A because if you set it to a proportion you get 1 7/9
Answer:
Half of a number is 15
Step-by-step explanation:
First of all, add commas between each option so it's easier to read I had a hard time figuring out what the options were because of this.
An equation is a statement that the values of two mathematical expressions are equal. An expression is a collection of symbols that jointly express a quantity. This means there has to be an equal sign when the phrases are put into numerical form.
Twice as much as a number: 2X
12 less than a number: X - 12
Half of a number is 15: X/2 = 15
The difference of 20 and a number: 20 - X
As you can see, only one of these phrases is an equation by definition, and that is X/2 = 15, or half of a number is 15. That's because it's the only one that values two expressions as equal.
