D a rectangle because it has four sides easy for abcd
Solution:
we are given that
A student has some $1 and $5 bills in his wallet.
Let there x $1 bills and y number of $5 bills.
He has a total of 14 bills that are worth $34.
So we can write


Now solve these two equations together using substitution as follows

Hence there are 9 $1 bills and 5 bills are of $5.
5. -6a-48
6. 36x+4
7. 30n+40
8. 1.8m+2
Yess
Let x be your first alloy
2/5x+7/10(30-x)=1/2(30)
4x+210-7x=150
3x=60
x=20
So, you need 20 lbs of the first alloy, and 10 parts of the second to make 30 lbs of half iron and half silver alloy!
Answer:
Step-by-step explanation:
Any equation with a product of variables, or with a variable in an exponent or denominator, is <em>not a linear equation</em>. Here, "product of variables" includes powers and roots—any expression with an exponent other than 1, or a total of exponents other than 1.