If 2a+b=10 ,ab=8 what is the value of 2a-b=?
2a + b = 10 SQUARE BOTH SIDES ( 2a + b)^2 = 100 4a^2 + b^2 + 4ab = 100 4a^2 + b^2 +4 (8) = 100 4a^2 + b^2 = 68 4a^2 + b^2 - 4ab = 68- 32 = 36 ( 2a - b)^2 = 36 2a- b = +6 OR -6 ANSWER
If a=7 and b=2 what is the value of 2ab?
Well, if a=7 and b=2 then 2ab = 2 * 7 * 2 = 2 * 14 = 28 hope it' ll help !!
If ab=10 and a^2+b^2=30 what is the value of (a+b)^2?
(a+b)^2 = a^2 + 2ab + b^2 = 30 +2(10) = 50
If a+b=7 and ab=4, what is the value of a^2+b^2?
(a + b)^2 = a^2 + 2ab + b^2 = 49 ab = 4 a^2 + b^2 = 49 - 2(4) = 49 - 8 = 41
If a-b=10 and a^2-b^2=20, what is the value of b?
a - b = 10 a² - b² = 20 Use substitution method... a = b + 10 (b + 10)² - b² = 20 b² + 20b + 100 - b² = 20 20b + 100 = 20 20b = -80 b = -80/20 b = -4 I hope this helps!
What is the value of ab if a2+b2=84 and a-b=8?
OK…As we know that :( a - b )^2 = a^2 + b^2 - 2 ab…..(i)From eq (1) :a^2 + b^2 = (a - b)^2 + 2 abGiven : a^2 + b^2 = 84 ; a - b =8..therefore ;=> 84 = (8)^2 - 2 ab=> 84 = 64 - 2 ab=> 84 - 64 = 2 ab=> 20 = 2 ab=> ab = 20/2 = 10…ans..Hence, the value of ab is 10..I hope you got your answer…
If a+b=6 and a-b=4 then what is the value of a²+b²?
One quick way to solve this will bea+ b =6(a+b)^2 = 36. ….(1)a- b = 4(a-b)^2 = 16…….(2)Adding (1) & (2) we get,(a+b)^2 + (a-b)^2=a^2+ b^2 +2ab +a^2+b^2–2ab =522(a^2+b^2) = 52a^2+b^2 = 26Alternate traditional waya+ b =6 …….(1)a- b = 4 …….(2)Subtracting (1) & (2) we get,2b = 6–4b = 1Substituting in (1) we get,1+ a = 6a = 5Therefore a^2+ b^2 =1*1 + 5*5 = 1+ 25 = 26
IF a - b=10 and a2 - b2=20, what is the value of b?
Correct answer is 10. a-b=10 or 2a-2b=20 ...(1) 2a-2b=20 (Given)...(2) Solving these, 4a=40 or a=10 Therfore, b=10.
If a+b=20 and a-b=8 then what is the value of a²+b²?
From the two equations we get the values of a & b as 7 &3. Such as a+b+a-b=10+4=14 or, 2a=14, a=7. Again a+b=10,or, b=10-a, or,b=10-7=3. So a^2+b^2=7^2+3^2=49+9=58