Question

solve this question by using method of elimination by substitution.
1. 0.2x + 0.1y=25
2(x-2)-1.6y=116

please solve by explaining. ​

Answer 1

Answer:

Given

equations

1. 0.2x + 0.1y=25

2. 2(x-2)-1.6y=116

To Find

solve the equation by elimination

Solution

2(x-2)-1.6y=116

➥2x- 4- 1.6y = 116

➥2x- 1.6y = 116 + 4

➥2x - 1.6 y= 120

Consider equation 1

0.2x + 0.1y=25

➥x= 25- 0.1 y/ 0.2. ........3.

★put the value of x in equation ....2

2 x ( 25 - 0.1 y / 0.2) - 1.6 y = 120

★ By solving this further we get :

➥y = 50

★substitute the value of y = 50 in equation 3.

➥x= 25 -0.1 x 50 /0.2

➥x= 25 - 5 /0.2

x= 100

Answer 2

Step-by-step explanation:

0.2x+0.1y=25...(i)

2(x−2)−16y=116...(ii)

By solving (ii) eq.

2x−4−16y=116

2x−1.6y=120

x−0.8y=60×2

0.2x+0.1y=25×8

⇒x−0.8y=60

1.6x+0.8y=200

2.6x=260

x=2162600

x=100

∴0.2(100)+0.1y=25

20+0.1y=25

0.1y=5

y=0