Math, asked by bhargu, 1 year ago

solve by elimination.
7x-8y-11=0 and x8-7y-7=0

Answers

Answered by Riasha
44
Simultaneous Equation:
7x-8y=11         8x-7y=7
* 7                   * -8
49x-56y=77    -64x+56y= -56
On subtracting we get,
- 15x= 21
x= 21/ -15
x= - 7/5
7* -7/5 - 8y =11
-49/5 - 8y=11
-8y = 104/5
y= -51/20


bhargu: sis can u answer my another question of elimination for 8 points i will ur answers the best. thanks a lot for ur help.i have some more questions 2marrow is my school pl. help me.ur the only one to help me.pl.pl.pl.
Riasha: listen but i am in class 10 preparing for icse tell me the question as a direct message and can i get back to u tommorrow?
Riasha: i need to study now :)
Riasha: pls mark this as best answer
bhargu: tommorrow is my school i have to complete this by tommarrow
Riasha: say fast
Riasha: how many more will it be a problem if i only give you the answer?
Answered by aditijaink283
2

Concept

Two equations can be solved by eliminating one of the variable terms. This is known as elimination method.

Given

2 equations

7x-8y-11=0

8x-7y-7=0

Find

we need to solve the equations using elimination method

Solution

We have

7x-8y-11=0 and 8x-7y-7=0

multiplying equation 1 by 8 we get

56x - 64y - 88 = 0

and multiplying 2nd equation by 7 we get

56x - 49y - 49 =0

Now we will subtract both the equations so as to eliminate the x term

56x - 64y - 88 - (56x - 49y - 49) = 0

56x - 64y - 88 - 56x + 49y - 49 = 0

- 64y - 88 + 49y + 49 = 0

- 64y - 88 + 49y + 49 = 0

-15y - 39 = 0

-15y = 39

y = -15/39

Thus, x will be

7x - 8(-15/39) - 11 = 0

7x = 11 - 120/39

7x = 309/39

x = 309/273

Thus, on solving the two equations, we get, x = 309/273 and y = -15/39

#SPJ2

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