Q.6. Find the mean proportion in the following:
i) 8, 16
ii) 1.25, 0.45
Q.7. If 3x+5y/3x-5y=7/3, find x:y
Q.8. If a : b = 5 : 3, find 5a-3b/5a+3b
Q.9. If (a + b + c) (a – b + c) = a²+b²+c² show that a,b,c are in continued proportion.
Q.10. Solve:
12x² + 18x + 42 = 2x + 3
18x² + 12x + 58 3x + 2
Answers
Answered by
9
Answer❀✿°᭄
Hope it helps you...!!!
Attachments:
Answered by
1
Answer:
To Prove : (a+b+c)(a−b+c)=a
2
+b
2
+c
2
Proof : a,b,c are in continued proportion.
∴
b
a
=
c
b
=k (let)
b=ck
a=bk=(ck)k =ck
2
L.H.S. =(ck
2
+ck+c)(ck
2
−ck+c)
=c
2
(k
2
+k+1)(k
2
−k+1)
=c
2
[(k
2
+1)
2
−(k)
2
]
=c
2
[k
4
+2k
2
+1−k
2
]
=c
2
[k
4
+k
2
+1]
R.H.S. =c
2
k
4
+c
2
k
2
+c
2
=c
2
[k
4
+k
2
+1]
L.H.S = R.H.S
9)
Step-by-step explanation:
mark me as a brainliest plz
Similar questions