It looks like ∆ is defined as
<em>a</em> ∆ <em>b</em> = (<em>a</em> + <em>b</em>)² + 5
If that's the case, then
1 ∆ (-4) = (1 + (-4))² + 5 = (-3)² + 5 = 9 + 5 = 14
Let's solve your inequality step-by-step.
<span><span><span>10x</span>+18</span><<span>−2
</span></span>Step 1: Subtract 18 from both sides.
<span><span><span><span>10x</span>+18</span>−18</span><<span><span>−2</span>−18
</span></span><span><span>10x</span><<span>−20
</span></span>Step 2: Divide both sides by 10.
<span><span><span>10x/</span>10</span><<span><span>−20/</span>10
</span></span><span>x<<span>−2
</span></span>Answer:
<span>x<<span>−<span>2</span></span></span>