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| 1. |
a3+b3=35 and a+b=5 then find a and b |
| Answer» a³+b³=( a+b)(a²-ab+b²) =(5) (a²-ab + b²)= 35 { a + b= 5} = (5) {a²-a(5-a)+(5- a)²}=35. {b=5- a} = (5) ( a²-5a+a²+25 + a²-10a)=35 =(5)(3a²-15a +25)= 35 =3a²-15 a+25= 35/5 = 3a²-15 a +25 =7 =3a²-15a +18= 0 = 3a²-9a -6a+18 = 0 =3a(a-3)-6(a-3)=0 =(a-3) (3a-6)=0 :.a=3 or a= 2 b =2or b=3 | |