Math word problem!!!! help?

2008-10-07 1:58 pm
The difference of two numbers is 33. If the bigger number is one less than thrice the smaller number, what is the sum of the two numbers?

回答 (6)

2008-10-07 2:04 pm
✔ 最佳答案
Let x = smaller number
3x - 1 = bigger number

-----

*(3x - 1) - x = 33

*2x = 33 + 1

*2x/2 = 34/2

*x = 17 (smaller number)

To get the bigger number:

3 (17) - 1 = 50 (bigger number)

The sum of the two numbers:

ANSWER: 17 + 50 = 67 (sum of the two numbers)

Checking:

50 - 17 = 33 (Correct!)
2008-10-07 2:40 pm
x - y = 33 (solve by using substitution)
x = 3y - 1

x - y = 33
(3y - 1) - y = 33
3y - 1 - y = 33
3y - y = 33 + 1
2y = 34
y = 34/2
y = 17

x - y = 33
x - 17 = 33
x = 33 + 17
x = 50

∴ x = 50 , y = 17
2008-10-07 2:19 pm
let no. be x,y
acc. to ques. we have
x-y=33
second case:
x=3y-1
x-3y= -1

solving simultaneouly by eliminating method we have
x-y=33 ---------------------- (1)
x-3y= -1 --------------------------------- (2)
(subtracting both we get)

2y=34
y=17
putting the value of "y" in equation 1 we get
x-y=33
x=33+y
x=33+17
x=50
ans. x=50,y=17
參考: myself
2008-10-07 2:08 pm
Let
bigger number = a,
smaller number = b

Difference of numbers is 33.
Therefore,
a - b = 33--------------------(1)

Bigger number is one less than thrice the smaller number.
Therefore,
a = 3b - 1--------------------(2)

Using the value of a from equation (2) in equation (1),
3b - 1 - b = 33
Or 2b - 1 = 33
Or 2b = 33 + 1
Or 2b = 34
Or b = 34/2
Or b = 17
Putting this value of b in (2),
a = 3*17 - 1 = 51 - 1 = 50
Sum of numbers = a + b = 50 + 17 = 67

Ans: 67
2008-10-07 2:07 pm
x - y = 33
and
x = 3y -1

now substitute the 2nd equation into the first:
3y -1 - y = 33

2y = 34
y =17,

and since x - y = 33,

x - 17 = 33
x = 50
2008-10-07 2:06 pm
let x = the larger #
let y = the smaller #


"The difference of two numbers is 33"
x - y = 33
x = 33+y [eq 1]


"the bigger number is one less than thrice the smaller number"
x = 3y - 1 [eq 2]


substituting eq 1 into eq 2
x = 33+y [eq 1]
x = 3y - 1 [eq 2]

33+y = 3y-1
33+1 = 3y - y
34 = 2y
y = 17


substitute this into eq 1:
x = 33+y [eq 1]
x = 33+17
x = 50



The sum of the two is 17+50 = 67























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