If `(a-b)=4` and `a b=2` , then `(a^2+b^2)=?` (a) 18 (b) 20 (c) 25 (d) None of these

If a cos theta+b sin theta=4 and a sin theta-b cos theta=3, then a^(2)+b^(2)=7(b)12 (c) 25 (d) None of these

If a+b+c=9 and ab+bc+ca=23 then a^(2)+b^(2)+c^(2)=35 (b) 58(c)127 (d) none of these

If a+b=5 and 3a+2b=20, then (3a+b) will be: (a)10 (b) 15 (c) 20 (d) 25

If a-b=3 and a^(2)+b^(2)=29, find the value of ab. (a) 10 (b) 12 (c) 15 (d) 18

[(125)^(2)-:50xx20]-:25=?(a)11(b)100 (c) 150(d)250(e) None of these

(20+8xx0.5)/(20-?)=12. Find the value in place of (?)( a) 2 (b) 8 (c) 18 (d) None of these

If 3a=4b=6c and a+b+c=27sqrt(29) then sqrt(a^(2)+b^(2)+c^(2)) is (a) 3sqrt(29) (b) 81 (c) 87 (d) None of these

(55.25)^(2)-637.5625=? (a) 25.25 (b) 625 (c) 1375 (d) 2415 (e) None of these

If a + b =8, a -b =4, then a^2 + b^2 is equal to (A) 20 (B) 40 (C ) 10 (D) 30

[(?)^(2)+(18)^(2)]-:125=3.56(a)11(b)12(c)14(d)15(e) None of these