Find the value of s and t in the following
Attachments:
GurdevSingh:
It’s basically related to factorisation, I can’t find out its answer though
Answers
Answered by
1
Given that x² +sx - 28 = (x+7)(x-t),
Expand the right hand side and compare the equation,
(x+7)(x-t), Expanding,
=> x² -tx + 7x -7t,
=> x² +x(7-t) -7t,
Now it is equal to x² +sx - 28 ,
Now compare both the equations, x² = x², and sx = x(7-t), and -28 = -7t,
I have compared these equations because this is the only method to solve these type of question,
=> -7t = -28,
=> t = 4,
Substituting this in sx to get value of x,
=> sx = x(7-t),
=> s = 7-t,
=> s = 3,
Therefore the value of s is +3 and value of t is +4,
Hope you understand, Have a great day !
Expand the right hand side and compare the equation,
(x+7)(x-t), Expanding,
=> x² -tx + 7x -7t,
=> x² +x(7-t) -7t,
Now it is equal to x² +sx - 28 ,
Now compare both the equations, x² = x², and sx = x(7-t), and -28 = -7t,
I have compared these equations because this is the only method to solve these type of question,
=> -7t = -28,
=> t = 4,
Substituting this in sx to get value of x,
=> sx = x(7-t),
=> s = 7-t,
=> s = 3,
Therefore the value of s is +3 and value of t is +4,
Hope you understand, Have a great day !
Similar questions