What is the meaning substitution in maths?

Answer 1

now think that:-

x=10

y=5

when you are asked to slove an equation say.....2x+4y=?.then we change the value of x and y into digits so we can work the problem out.

now since x=10.

then 2x is= 10*2

which is 20.

y=5

then 4y is=5*4

which is 20

now we have the value of 2X and 4Yso lets use it to get the answer

2x+4y=?

2x=20

2y=20

so now since we know the values of 2x 4y lets us write their values in the equation instead

so now it is 20+20=?

the answer is 40

the changing of the algebric structure 2x into 20 in the equation is called substitution