2(a+3)+9(7-b)=0
3(a-1)+4(b-4)=0 find the value of a and b
Answers
Step-by-step explanation:
2(a + 3 ) + 9 (7 - b ) = 0
2a + 6 + 63 - 9b = 0
2a + 69 - 9b = 0
2a - 9b = -69
take this as equation 1
3(a -1) + 4(b - 4 ) = 0
3a - 3 + 4b -16 = 0
= 3a + 4b = 19
take this as equation 2
adding equation 1 and 2
2a - 9b = -69
(+)3a + 4b = 19
= 5a - 5b = - 50
= 5 (a - b ) = - 50
= (a - b ) = - 10
= a = b -10
substitute a as b + 10 in equation 1
= 2a - 9b = -69
= 2(b-10) - 9b = -69
2b - 20 - 9b = -69
- 7b = -69 + 20
- 7b = - 49
b = 7
a = b + 10
= 7 + 10
= 17
a = 17
Step-by-step explanation:
2a+6+63-9b=o
2a+69-9b=0
2a-9b=-69=>(1)
3a-3+4b-16=0
3a+4b-19=0
3a+4b=19=>(2)
epuation(1)multiply by 3
(2a-9b=-69)×3
=.6a-27b=-207=>(3)
epuation(2)multiply by 2
(3a+4b=38)×2
= 6a+8b=38=>(4)
epuation(3)&(4) by elemination method
=. 6a-27b=-207
6a+ 8b= 38
-. -. -
-35b=-245
b=-245/-35
b=7
(b=7)put in epuation2
3a+4b=19
3a+4(7)=19
3a+28=19
3a=19-28
3a=9
a=9/3
a=3