Hello,
Penny==>a*10 (a is an integer)
Kenny==>b*18 (b is an integer)
a*10=b*18==>a=9*b/5 ==>b=5+n*5
a=9*(5+5*n)/5=9*(1+n)=9+9n
If n=0 then a=9 and b=5 :Number od cards: 9*10=10, 5*18=90
if n=1 then a=19 and b=10: Number of cards: 19*10=190>100 to exclude.
So number of cards=90
The last one isn’t
there can’t be more than 1 of the same x value
Answer:
x = -5 and y = 3
Step-by-step explanation:
There are two equations :
3x − 2y = −21 ....(1)
2x + 5y = 5 ......(2)
Multiply equation (1) by 2 and equation (2) by 3.
6x - 4y = -42 ...(3)
6x + 15y = 15 ....(4)
Subtract equation (4) from (3) :
6x - 4y - (6x + 15y) = -42 -15
-4y -15y = -57
-19y = -57
y = 3
Put y = 3 in equation (2) :
2x + 5(3) = 5
2x = 5-15
2x = -10
x = -5
So, the value of x is (-5) and y = 3.
So,
We know that we cannot add or subtract quantities of the same kind.
-18xy can only be added/subtracted to 4yx, which is the same as 4xy. The result would be -14xy, or -14yx.
The correct option is B.
7x10^4
Because there are 4 sets of 10