Given that $y= 4x - 3$, work out the value of $x$ when $y = 11$

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Given that $y= 4x - 3$, work out the value of $x$ when $y = 11$

I don't get this because i can't think of a number that you can multiply by 4 then subtract 3 to get 11 or am i missing something?

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2 Answers

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You have to solve the equation: $$11 = 4 x - 3.$$ Using the basic properties of equations you get $$x=\frac{11 + 3}{4}$$ i.e. $$ x = 3.5. $$

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If you would like a step by step solution: So if $y=4x-3$ then add 3 to each side to get: $y+3=4x$.

Next just divide both sides by 4 to get $x = (y+3)\div4$.

Now the final step is to substitute your value of 11 in for $y$ which will give you $x = (11+3)\div4 = 3.5$

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