Question

x-3y+5=0;x+y=55
answer the following question by substitution method. ​

Answer 1

➤ Answer

• x = 40 and y = 15.

➤ Given

• A linear equation in two variables i.e. x - 3y + 5 = 0 and x + y = 55.

➤ To Find

• The value of x and y using substitution method.

➤ Step By Step Explanation

Given a linear equation in two variables i.e. x - 3y + 5 = 0 and x + y = 55.

So let's do it !!

➠ Arrangement

Let's arrange the equation in a systematic order.

x - 3y + 5 = 0 => x - 3y = -5

x + y = 55 => x + y = 55

➠ Assumption

Let us assume that x - 3y = -5 be equation 1 and x + y = 55 be equation 2.

➠ Solution

First we need to find the value of x from first equation.

$\longmapsto\tt x - 3y = - 5 \\ \\ \longmapsto\tt x = - 5 + 3y$

Now, let's substitute the value of x in second equation.

$\longmapsto\tt x + y = 55 \\ \\ \longmapsto\tt( - 5 + 3y) + y = 55 \\ \\ \longmapsto\tt - 5 + 3y + y = 55 \\ \\ \longmapsto\tt - 5 + 4y = 55 \\ \\ \longmapsto\tt 4y = 55 + 5 \\ \\ \longmapsto\tt 4y = 60 \\ \\ \longmapsto\tt y = \cancel\cfrac{60}{4} \\ \\\longmapsto\tt{\green{y = 15}}$

Now, x = 55 - y => 55 - (15) => 40.

Therefore, x = 40 and y = 15.

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