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# algebra

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hi can someone help me with my sons algebra homework please- i'm a bit rusty. its the pluses and minuses that are confusing me! Thanks in anticipation

a) 5-4x = 3 + x

b) 8n +11 = 1 + 6n

c) 6- x = 11 -3x

d) 7 = 3y = 5y -2

a) 5-4x = 3 + x

b) 8n +11 = 1 + 6n

c) 6- x = 11 -3x

d) 7 = 3y = 5y -2

# Answers

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For more on marking an answer as the "Best Answer", please visit our FAQ.reverse equation easier to have larger amount of x on the left hand side [+x > -4x]

3 + x = 5 - 4x

(add 4x to both sides)

3 + 5x = 5

(subtract 3 from both sides)

5x = 2

(divide by 5)

x =0.4

b) 8n + 11 = 1 + 6n

(subtract 6n from both sides

2n + 11 = 1

(subtract 11 from both sides)

2n = -10

(divide by 2)

n = -5

c) 6 - x = 11 - 3x

(add 3x to both sides)

6 + 2x = 11

(subtract 6 from both sides)

2x = 5

(divide by 2)

x = 2.5

d) I guess you mean - and typed = instead of +

7 + 3y = 5y -2

reverse the equation as 5y > 3y

5y - 2 = 7 + 3y

(subtract 3y from both sides)

2y - 2 = 7

(add 2 to both sides)

2y = 9

(divide by 2)

y = 4.5

The key to the above method

if you want to eliminate something from one side of the equation do the inverse (opposite of what you want to eliminate ) to both sides of the equation.

If you want to eliminate -x then add x to both sides

If you want to eliminate +5 then subtract 5 to both sides.

always trying to change the equations to something of the order 5x = 18 or 4x = 6 etc then divide to find the value of the unknown