標題:
發問:
the sum of two number is 53 and the difference of the two number is 5.find the two numbers. (方程式) 唔該!train up mathematics s2 to s3 更新: 1a)Solve 2a+b=4 a-2b=7 1b)Hence solve 2/x+1/y=4 1/x-2/y=7 3)Solve the following simultanous equations with three unknowns a+b+c=4(1) 2a-b+c=0(2) 2a+b-3c=10(3) 更新 2: 4)two simultanous linear equations in two unknowns have0,1 or infinite number of solutions. How do we know that?State the resoning. 再次唔該唔該唔該!!
最佳解答:
Let the smaller number and larger number be x and y respectively. x+y=53 x+5=y 2x+5=53 x=24 y=29 1a.2a+b=4 a-2b=7 a=2b+7 (4b+14)+b=4 5b=-10 b=-2 2a-2=4 a=3 1b.2/x+1/y=4 1/x-2/y=7 2y+x=4xy y-2x=7xy (y-2x)-(2y+x)=7xy-4xy -y-3x=3xy y+3x=-3xy y=-3xy-3x y/3x=y-1 y/y-1=3x x=y/3y-1 3. a+b+c=4 2a-b+c=0 2a+b-3c=10 b-3c-(-b+c)=10 2b-4c=10 b-2c=5 b-2c-(a+b+c)=1 -3c-a=1 a-4c=6 a=6+4c -3c-6-4c=1 -7c-6=1 -7c=7 c=-1 a=2 b=-3 4.The last question I do not know how to help you.
其他解答:
Let x be the larger number, and (53-x) be the smaller number. x - (53-x) = 5 2x - 53 = 5 2x = 5 + 53 2x = 58 x = 29 So, the two numbers are 29 and 24 respectively. 2008-07-17 14:41:03 補充： 我驚你可能唔明點解 the smaller number 會係 (53-x) , 所以係呢度補充番個解釋: 由於 the larger number 加 the smaller number 等於 53. 所以 當我地代x 為 the larger number, 咁 the smaller number 自然會係 53-x 啦!!|||||let x be the larger no., y be the smaller number. x + y = 53 -(1) x - y = 5 -(2) (1)+(2): 2x = 58 x = 29 Sub x = 29 into (2) 29 - y = 5 y = 24 the two numbers are 29 and 24.
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form2數學題(15分)發問:
the sum of two number is 53 and the difference of the two number is 5.find the two numbers. (方程式) 唔該!train up mathematics s2 to s3 更新: 1a)Solve 2a+b=4 a-2b=7 1b)Hence solve 2/x+1/y=4 1/x-2/y=7 3)Solve the following simultanous equations with three unknowns a+b+c=4(1) 2a-b+c=0(2) 2a+b-3c=10(3) 更新 2: 4)two simultanous linear equations in two unknowns have0,1 or infinite number of solutions. How do we know that?State the resoning. 再次唔該唔該唔該!!
最佳解答:
Let the smaller number and larger number be x and y respectively. x+y=53 x+5=y 2x+5=53 x=24 y=29 1a.2a+b=4 a-2b=7 a=2b+7 (4b+14)+b=4 5b=-10 b=-2 2a-2=4 a=3 1b.2/x+1/y=4 1/x-2/y=7 2y+x=4xy y-2x=7xy (y-2x)-(2y+x)=7xy-4xy -y-3x=3xy y+3x=-3xy y=-3xy-3x y/3x=y-1 y/y-1=3x x=y/3y-1 3. a+b+c=4 2a-b+c=0 2a+b-3c=10 b-3c-(-b+c)=10 2b-4c=10 b-2c=5 b-2c-(a+b+c)=1 -3c-a=1 a-4c=6 a=6+4c -3c-6-4c=1 -7c-6=1 -7c=7 c=-1 a=2 b=-3 4.The last question I do not know how to help you.
其他解答:
Let x be the larger number, and (53-x) be the smaller number. x - (53-x) = 5 2x - 53 = 5 2x = 5 + 53 2x = 58 x = 29 So, the two numbers are 29 and 24 respectively. 2008-07-17 14:41:03 補充： 我驚你可能唔明點解 the smaller number 會係 (53-x) , 所以係呢度補充番個解釋: 由於 the larger number 加 the smaller number 等於 53. 所以 當我地代x 為 the larger number, 咁 the smaller number 自然會係 53-x 啦!!|||||let x be the larger no., y be the smaller number. x + y = 53 -(1) x - y = 5 -(2) (1)+(2): 2x = 58 x = 29 Sub x = 29 into (2) 29 - y = 5 y = 24 the two numbers are 29 and 24.
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