1. If a = 2 and b= 3, find the value of 17a-5b. 2. If x = 1, y = 2 and 2 = 3, find the value of 5x + 6y - 2. 3. If a = 3,b= 1 and c=-2, find the value of a2 + b2 + C2 + 2ab + 2bc + 2ca. 4. If x=2, y= 3 and z= 1, find the value of 3x - 2y + 72 4x - 3y + 5z 5. If x = 4, y = 6 and z = 2, find the value of x + y3 - 3.ryz. Add the following expressions 6. x + y, 5x + 3y + 7z and 3x - 8y + 2z. 7. a2 2ab + b2, 2ab + a² + b2, 4a2 - 4ab-b2 and a² – 62. -
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Answer:
Step-by-step explanation:
Correct option is A)
The given equations are
2
a
+3
b
=17 .....(i)
2
a+2
−3
b+1
=5 ...(ii)
⟹2
a
×2
2
−3
b
×3=5
⟹4×2
a
−3×3
b
=5
We put 2
a
=x & 3
b
=y.
Then the equations become
x+y=17 ...........(iii) &
4x−3y=5 ........(iv).
(iii)×4⟶4x+4y=68.....(v).
(iv)−(v)⟶7y=63
⟹y=9=3
2
.
∴3
b
=3
2
⟹b=2.
Again putting y=9 in (iii),
x=17−y=17−9=8=2
3
So 2
a
=2
3
i.e a=3.
So, (a,b)=(3,2).
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