Question

Solve for x and y:

0.4x-1.5y=6.5,
0.3x+0.2y=0.9.​

Answer 1

Answer:

x = 5 and y = 3

Step-by-step explanation:

Multiplying each of the equations by 10 , we get

4x−15y=65 … (i)

3x+2y=9 … (ii)

Multiplying (i) by 2 and (ii) 15 and adding, we get

8x+45x=130+135

⇒53x=265

⇒x=26553=5

Putting x=5 in (ii), we get

15+2y=9⇒2y=9−15⇒2y=−6⇒y=−3

Hence, x=5 and y=−3

Answer 2

$\bf{\underline{\red{Correct\:Question:-}}}$

✓✓Solve for x and y:

• 0.4x - 1.5y = 6.5
• 0.3x + 0.2y = 0.9.

$\bf{\underline{\orange{AnSwEr:-}}}$

❍ $\bf\purple{{x=5\:and\:y=-3}}$

$\bf{\underline{\green{Explanation:-}}}$

$\bf\:The\:given\: equation\:are,$

• $\bf\:0.4x - 1.5y = 6.5.........(i)$

• $\bf\:0.3x + 0.2y = 0.9.......(ii)$

Multiplying each one of the equations by 10, we get:

• $\bf\:4x-15y=65..........(iii)$

• $\bf\:3x+2y=9..............(iv)$

Multiplying (iii) by 2 and (iv) by 15 ,we get:

• $\bf\:8x-30y=130..........(v)$

• $\bf\:45x+30y=135.......(vi)$

Adding (v) and (vi) ,we get:

$\bf\implies\:53x=265$

$\bf\implies\:x=\dfrac{265}{53}$

$\bf\green{{\implies\:x=5}}$

putting x = 5 in (iii) , we get:-

$\bf\implies\:(4\times\:5)-15y=65$

$\bf\implies\:20-15y=65$

$\bf\implies\:-15y=45$

$\bf\implies\:y=\dfrac{45}{-15}$

$\bf\pink{{\implies\:y=-3}}$

$\bf\therefore\blue{{x=5\:and\:y=-3}}$$\bf\blue{{is\:the\: required\: Solution}}$

$\bf\star\red{{More\: Information...!!!!!}}$

$\bf\: Substitution\: Method$

❍ Suppose we are given two linear equation in x and y.for solving these equations by the substitution method ,we proceed according to the following steps:-

• Step 1. Express y in terms of x in one of the given equations.

• Step 2. substitute this value of y in terms of x in the other equation.This gives a linear equation in x.

• Step 3. Solve the linear equation in x obtained in step 2.

• Step 4. substitute this value of x in the relation taken in step 1 to obtained a linear equation in y.

• Step 5. Solve the above linear equation in y to get the value of y.