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Question Number 196056 by mr W last updated on 17/Aug/23

solve  (√(2x+3))−(√(3x+8))=(√(3x+4))−(√(2x+7))

solve2x+33x+8=3x+42x+7

Answered by cortano12 last updated on 17/Aug/23

 (√u) −(√(v+4)) =(√v)−(√(u+4))    (√u)−(√v) = (√(v+4))−(√(u+4))    u+v−2(√(uv)) = u+v+8−2(√((u+4)(v+4)))    (√((u+4)(v+4))) = 4+(√(uv))    uv+4(u+v)+16=16+uv+8(√(uv))     u+v = 2(√(uv))     ((√u)−(√v) )= 0     (√u) = (√v) ; [  { ((u=2x+3)),((v=3x+4)) :} ]     ⇔ 3x+4 = 2x+3    ⇔ x=−1

uv+4=vu+4uv=v+4u+4u+v2uv=u+v+82(u+4)(v+4)(u+4)(v+4)=4+uvuv+4(u+v)+16=16+uv+8uvu+v=2uv(uv)=0u=v;[{u=2x+3v=3x+4]3x+4=2x+3x=1

Commented by mr W last updated on 17/Aug/23

very nice!

verynice!

Answered by mr W last updated on 17/Aug/23

an other way:  (√(2x+7))+(√(2x+3))=(√(3x+8))+(√(3x+4))   ...(i)  ((((√(2x+7))+(√(2x+3)))((√(2x+7))−(√(2x+3))))/( (√(2x+7))−(√(2x+3))))=((((√(3x+8))+(√(3x+4)))((√(3x+8))−(√(3x+4))))/( (√(3x+7))−(√(3x+4))))  (4/( (√(2x+7))−(√(2x+3))))=(4/( (√(3x+7))−(√(3x+4))))  ⇒(√(2x+7))−(√(2x+3))=(√(3x+8))−(√(3x+4))   ...(ii)  (i)+(ii):  2(√(2x+7))=2(√(3x+8))  2x+7=3x+8  ⇒x=−1 ✓

anotherway:2x+7+2x+3=3x+8+3x+4...(i)(2x+7+2x+3)(2x+72x+3)2x+72x+3=(3x+8+3x+4)(3x+83x+4)3x+73x+442x+72x+3=43x+73x+42x+72x+3=3x+83x+4...(ii)(i)+(ii):22x+7=23x+82x+7=3x+8x=1

Commented by MM42 last updated on 17/Aug/23

and your solution very nice

andyoursolutionverynice

Answered by MM42 last updated on 17/Aug/23

And other way  2x+3+3x+8−2(√(6x^2 +25x+24))=3x+4+2x+7−2(√(6x^2 +29x+28))  ⇒(√(6x^2 +25x+24))=(√(6x^2 +29x+28))  ⇒x=−1 ✓

Andotherway2x+3+3x+826x2+25x+24=3x+4+2x+726x2+29x+286x2+25x+24=6x2+29x+28x=1

Answered by Rasheed.Sindhi last updated on 17/Aug/23

(√(2x+3))−(√(3x+8))=(√(3x+4))−(√(2x+7)) _(−)   (√(2x+5−2)) +(√(2x+5+2)) =(√(3x+6−2)) +(√(3x+6+2))       2x+5=a  , 3x+6=b  (√(a−2)) +(√(a+2)) =(√(b−2)) +(√(b+2)) =c (say)      (√(a−2)) +(√(a+2)) =c.........(i)    ((√(a−2)) )^2 −((√(a+2)) )^2  =(a−2)−(a+2)=−4...(ii)  (ii)/(i):     (√(a−2)) −(√(a+2)) =((−4)/c).......(iii)  (i)+(iii):     2(√(a−2)) =c−(4/c).....(iv)  Similarly,      2(√(b−2)) =c−(4/c).....(v)  (iv) & (v): 2(√(a−2)) =2(√(b−2))   a=b⇒2x+5=3x+6                x=−1

2x+33x+8=3x+42x+72x+52+2x+5+2=3x+62+3x+6+22x+5=a,3x+6=ba2+a+2=b2+b+2=c(say)a2+a+2=c.........(i)(a2)2(a+2)2=(a2)(a+2)=4...(ii)(ii)/(i):a2a+2=4c.......(iii)(i)+(iii):2a2=c4c.....(iv)Similarly,2b2=c4c.....(v)(iv)&(v):2a2=2b2a=b2x+5=3x+6x=1

Answered by Frix last updated on 17/Aug/23

Just guessing. If there′s a “nice” solution  2x+3=3x+4∧3x+8=2x+7  x=−1              ∧x=−1

Justguessing.Iftheresanicesolution2x+3=3x+43x+8=2x+7x=1x=1

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