X + 2 y = 5
y=2x – 15

one solution : (7 ; - 1)

Step-by-step explanation:

hello :

X + 2 y = 5   ...(*)

y=2x – 15...(**)

use(**) put the value of y into (*) :   x+2(2x-15)=5

x+4x-30=5

5x= 35

x=35/5=7

but : y =2x-15

so : y=2(7)-15=-1

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b