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Can someone please explain pre-algebra problems? (example: 2x - 7 = 3 (x - 4) or 5x + 3 < 4x - 1) questions like those confuse me. I have no clue on where to start for any of them.

User Justin Lok
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1 Answer

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1. if 4 + 4 = x you'd say x = 8

pre-algebra wants you to get used to using letters like x in math

where x = the answer

put x on one side of the equal sign & the numbers on the other side

letters like x help people do bigger & is more complicated math

2. in real life math the symbols

less than or < means "up to" or "at most" &

great than or > means "at least"

which helps with things like money & prices

like "that chair is at least $100" or "chair > $100"

3. negative numbers are backwards:

-4 -5 -6 are considered smaller than -3

Answer:

in pre algebra

you have to do the math so that you

put x on one side of the equal sign &

the numbers on the other side

x = the answer

for

1.

2x - 7 = 3 (x - 4)

multiply 3 with (x - 4)

you do this by

multiplying 3 with x and

multiplying 3 with- 4

2x - 7 = 3 (x - 4)

2x - 7 = 3x - 12

put x on one side of the equal sign & the numbers on the other side

2x - 7 = 3x - 12

-2x = -2x

2x -2x = 0 & 7 comes down.

3x -2x = 1x & - 12 comes down

0 - 7 = 1x - 12

add 12 on both sides

- 12 + 12 = 0

- 7 + 12 is the same as 12 - 7 which is 5

0 + 5 = 1x - 0

you dont have to show the 0

& if its 1x you you dont have to show the 1

5 = x or x = 5

2.

5x + 3 < 4x - 1

for now treat < like an equal sign

in real life math the symbols < & > mean at least or at most

which helps with things about money

5x + 3 < 4x - 1

subtract -4x on both sides

5x + 3 < 4x - 1

-4x -4x

1x + 3 < 0 - 1

subtract 3 on both sides

1x + 3 < 0 - 1

1x - 3 < 0 - 3

x < - 3

answer means the answer is

at most -4

up to -4

& less than -3 because

-4 is the highest number thats less than -3

negative numbers are backwards

-4 -5 -6 are considered smaller than -3

Explanation:

x is called a variable

if someone wrote

4 + 4 = x

you'd say x = 8, right?

pre-algebra wants you to get used to using letters like x in math

because letters like x help people do math that has much bigger numbers & is more complicated

this higher math companies like banks & hospitals help people deal with money & medicine

problems in pre-algebra

the answers usually look like

x = the answer

User Thomas Danecker
by
8.3k points

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