We are given ratio nickel to zinc to copper = 2:7:9.
From this ratio we can see that <em>ratio of nickel to zinc is 2:7</em>.
Let us assume number of pounds of nickel have to be used to create alloy that contains 4.9 lb of zinc is x pounds.
So, we can setup a proportion as :
x : 4.9 = 2:7
Or
On cross multiplication, we get
7x= 4.9× 2
7x = 9.8
Dividing both sides by 7, we get
x = 1.4.
<h3>Therefore, 1.4 pounds of nickel have to be used to create alloy that contains 4.9 lb of zinc.</h3><h3 />Answer:
When a graph has 2 x-intercepts, it will have positive discriminant & when a graph has NO x-intercepts, it will have negative discriminant.
Step-by-step explanation:
In a quadratic equation, the discriminant is the value of . This is "under the square root sign" when solving using quadratic formula.
Thus, there can be 3 possibilities:
1. Discriminant is 0 ( 2 equal real roots - meaning 1 touching point at the x-axis in the graph)
2. Discriminant can be positive ( 2 distinct real roots - meaning 2 cutting point in the x axis)
3. Discriminant can be negative ( 2 complex roots - meaning NO cutting point in x-axis)
Thus, when a graph has 2 x-intercepts, it will have positive discriminant & when a graph has NO x-intercepts, it will have negative discriminant.
